Puzzle Books & Mystery Game Library

The collection4 books

Your space⌑My AccountYour story so far The Apprentice's TestFree to play The Alchemist's StudyIn testing The Keeper's Log — Flannan IslesIn development

Choose a spine to see its story and files. Use ← → to browse.

Inside the selected book

The Apprentice's Test

The collection / Stories taking shape

Free to play

Shelf position 01 / Free to play

The Apprentice's Test

A free twenty-five-minute browser-only induction. No printer is required to play. Completion offers an optional Apprentice sigil in single-colour STL or multicolour 3MF. It is a standalone keepsake with no Codex mounting interface.

Format: A free browser case. No printer required.
Availability: Free to play. Sign in to keep your Apprentice progress across devices.

Open the free case file →

Nothing to print before you play.

The Apprentice is entirely in your browser. Finish its five proofs to discover an optional sigil and the reusable Codex.

Finding your place…

The Apprentice’s Test / Your discoveries

A little something to keep.

Finish the Apprentice to discover your optional print files.

The Apprentice sigil

A keepsake of your five proofs: a sculpted eye, made to match the colour of your Apprentice book. Choose outlined lettering for a single-colour print or the original flush colour inlays. This optional 50 mm sigil is yours to print after the test; no print is needed to complete the game.

Optional personal printing. Choose one colour edition; you do not need both.

Single-colourSTL ↓Multicolour3MF ↓

Single-colour printing guidance

apprentice-sigil-v08-single-colour-r01.stl

Print one assembled sigil at 100% scale in millimetres, with the flat reverse on the bed and eye facing up. It is 50 mm across and 4 mm thick. The front name and reverse letter have 0.35 mm-wide, 0.30 mm-deep outside outlines; their faces stay flat. Use one filament and paint if desired. Select your own printer, nozzle and material: this STL includes no printer settings or G-code. Inspect the shallow grooves in a fresh slice and check the first layer before printing. Digitally checked and approved for personal download. The creator reported a successful print of this edition on 27 September 2026; other printers, materials, wear and book-storage fit are not independently validated.

Print settings

Orientation: Flat reverse on the bed, eye facing up.
Layer height: Select for your printer and inspect the 0.30 mm-deep grooves.
Supports: Inspect a fresh slice; keep the flat reverse on the bed.
Material: One filament matching your Apprentice book; optional paint.
Nozzle: No embedded profile; select your own nozzle and inspect outline paths.
Walls: Use your own checked printer profile.
Infill: Use your own checked printer profile.
Bed adhesion: Check the underside outline in the first layer.
Scale: 100%, millimetres; 50 mm diameter and 4 mm thickness.
Assembly & finishing: One connected sigil; no separate pieces to assemble.
Print testing: Creator reports a successful print of this single-colour edition on 27 September 2026. Digitally checked and approved for download; other printers, materials, wear and book-storage fit are not independently validated.

Use the guidance for this exact file and edition. Where a setting is not specified, check the print instructions or ask for help before printing.

Personal printing only. You may print this Apprentice Sigil V08 for your own personal, non-commercial use. Do not redistribute or sell the files or printed copies. Commercial makers need a separate written agreement with The Printed Secret.

Download this file ↓

Multicolour printing guidance

apprentice-sigil-v08.3mf

Open this assembled 3MF in a compatible slicer. Keep all four aligned regions together at 100% scale; the sigil is 50 mm across and 4 mm thick. Use three colours: a body colour matching your Apprentice book, gold face details and cream reverse lettering. The lettering is flush with the surface. Saved Flashforge Creator 5 Pro / 0.4 mm / PLA settings: 0.20 mm layers, 0.25 mm first layer, three walls, 10% infill, supports and brim off. Select your actual printer and material, inspect a fresh slice, and do not send another printer’s G-code. This project contains no G-code. Creator test print accepted for this exact file; other printers, material combinations, wear and book-storage fit are not independently validated.

Print settings

Orientation: Flat reverse on the bed; keep all four colour regions aligned.
Layer height: Saved 0.20 mm; first layer 0.25 mm.
Supports: Saved off; inspect a fresh slice.
Material: Saved PLA; use the body colour of your Apprentice book with contrasting face and reverse colours.
Nozzle: Saved 0.4 mm; select your own printer.
Walls: Saved three walls.
Infill: Saved 10%.
Bed adhesion: Saved brim off; check your first-layer adhesion.
Scale: 100%, millimetres; 50 mm diameter and 4 mm overall thickness.
Assembly & finishing: Print as one assembled object. Do not split or auto-arrange its colour regions.
Print testing: Creator reports acceptance of this exact test print. Other printers, materials, wear and book-storage fit are not independently validated.

Use the guidance for this exact file and edition. Where a setting is not specified, check the print instructions or ask for help before printing.

Download this file ↓

The Alchemist's Study — atmosphere artwork

In testing

Shelf position 02 / In testing

The Alchemist's Study

Aurelian Vane vanished from his own study in 1698, leaving the door bolted from the inside. The Alchemist’s Study is coming soon and not on sale; 3D-printed parts are required, and the final kit is still being tested.

Format: A physical book and browser. Access to a 3D printer or an independent maker will be required.
Availability: In testing. Private testing by invitation. Public play and sales are closed.

Testers can sign in and redeem their invitation at the private testing page.

The Alchemist's Study / Print files

Prepare the book. Open the mystery.

When this physical edition is released, choose a single-colour or multicolour Codex first, then the game book. Game-specific pieces will be packaged with the book.

Print files for this case are not released yet. Each released file will include its own material, layer height, supports and orientation guidance.

Read the printing guide →

The Alchemist's Study / Your progress

Your story starts here.

Private test progress is kept separately from customer games. Sign in at the testing page to resume your invitation.

The Keeper's Log — Flannan Isles — atmosphere artwork

In development

Shelf position 03 / In development

The Keeper's Log — Flannan Isles

Three lighthouse keepers disappeared from Eilean Mòr in December 1900. Examine the surviving accounts, compare the traces, and decide what the evidence can honestly support. At your desk, an unexplained pattern begins to return.

Format: A physical book and browser. Access to a 3D printer or an independent maker will be required.
Availability: In development. This case is not available to play or download.

Not yet available to play or buy.

Read the case file →

The Keeper's Log — Flannan Isles / Print files

Prepare the book. Open the mystery.

When this physical edition is released, choose a single-colour or multicolour Codex first, then the game book. Game-specific pieces will be packaged with the book.

Print files for this case are not released yet. Each released file will include its own material, layer height, supports and orientation guidance.

Read the printing guide →

The Keeper's Log — Flannan Isles / Your progress

Your story starts here.

This case is in development. Its game and saved progress will appear here when it is released.

Your personal archive

Your story so far.

Keep your mysteries and discoveries together. Sign in to save Apprentice progress across devices, or continue playing as a guest in this browser.

Open your account →

Finding your place…

Discovered through the Apprentice

The Codex

The reusable Codex book and shared tools, with single-colour and multicolour downloads for personal printing. Game-specific middle wheel rings come with the relevant games.

Print it for future physical mysteries. The Apprentice needs no printed parts.

The Codex

The reusable Codex book and shared tools, with single-colour and multicolour downloads for personal printing. Game-specific middle wheel rings come with the relevant games.

Optional personal printing. Choose one colour edition; you do not need both.

Single-colourZIP ↓MulticolourZIP ↓

Single-colour printing guidance

codex-and-objects-single-colour.3mf

Open as a two-plate project in a compatible slicer. Saved Flashforge Creator 5 Pro / 0.4 mm nozzle / PLA settings: 0.20 mm layers, 0.25 mm first layer, three walls, 10% infill; supports and brim off. Check your actual printer/material and slice again; no G-code is included. Keep book components aligned. All parts use filament 1; grille markings are engraved 0.30 mm for optional painting. Print one set, not both editions. Game-specific middle wheel rings are supplied separately with their games. Digital geometry checks passed. A fresh slice and exact-edition physical print, fit, movement, legibility and wear checks remain unverified. The decorative wheel centre includes 0.35 mm-wide, 0.30 mm-deep underside outlines with flat letter faces; all other parts are unchanged. Inspect these grooves in the first layers. If upgrading an existing kit, reprint only the centre retainer.

Print settings

Orientation: Retain the supplied two-plate layout and upright book pose.
Layer height: Saved 0.20 mm; first layer 0.25 mm.
Supports: Saved off; inspect bridges and overhangs in a fresh slice.
Material: Saved Generic PLA; check your actual material.
Nozzle: Saved 0.4 mm; verify your actual printer.
Walls: Saved three walls.
Infill: Saved 10%.
Bed adhesion: Saved textured PEI and brim off; check first-layer adhesion.
Scale: 100%, millimetres. Do not scale to fit a bed.
Assembly & finishing: Print one set. Do not split aligned book/grille regions. Game-specific middle rings and their assembly directions come with the relevant games. Keep coatings out of hinges, threads and openings.
Print testing: Digital geometry checks passed. A fresh slice and exact-edition physical print, fit, movement, legibility and wear checks remain unverified.

Use the guidance for this exact file and edition. Where a setting is not specified, check the print instructions or ask for help before printing.

Personal printing only. You may print these files for your own non-commercial use. Do not redistribute or sell the files or printed copies. Commercial makers need a separate written agreement with The Printed Secret. Downloading does not grant commercial rights.

Download this file ↓

01-codex-portable-single-colour.3mf

Portable 3MF geometry only. Keep all six aligned material regions together as ONE object using ONE filament. Preserve the supplied upright pose for print-in-place hinges; never split, auto-arrange or scale the regions. Use your own printer profile.

Print settings

Orientation: Upright book as supplied; keep all component regions aligned.
Layer height: Not specified for this file.
Supports: Not specified for this file.
Material: Not specified for this file.
Nozzle: Not specified for this file.
Walls: Not specified for this file.
Infill: Not specified for this file.
Bed adhesion: Not specified for this file.
Scale: 100%, millimetres. Do not scale to fit a bed.
Assembly & finishing: Print one set. Do not split aligned book/grille regions. Game-specific middle rings and their assembly directions come with the relevant games. Keep coatings out of hinges, threads and openings.
Print testing: Digital geometry checks passed. A fresh slice and exact-edition physical print, fit, movement, legibility and wear checks remain unverified.

Use the guidance for this exact file and edition. Where a setting is not specified, check the print instructions or ask for help before printing.

Download this file ↓

02-wheel-base.stl

Print one at 100% scale in millimetres using the supplied underside and your own printer profile. Keep paint out of mating and moving surfaces. The wheel carrier requires the matching middle ring from the game; do not print duplicate parts from the native project.

Print settings

Orientation: Supplied flat underside on the bed; keep any component regions aligned.
Layer height: Not specified for this file.
Supports: Not specified for this file.
Material: Not specified for this file.
Nozzle: Not specified for this file.
Walls: Not specified for this file.
Infill: Not specified for this file.
Bed adhesion: Not specified for this file.
Scale: 100%, millimetres. Do not scale to fit a bed.
Assembly & finishing: Print one set. Do not split aligned book/grille regions. Game-specific middle rings and their assembly directions come with the relevant games. Keep coatings out of hinges, threads and openings.
Print testing: Digital geometry checks passed. A fresh slice and exact-edition physical print, fit, movement, legibility and wear checks remain unverified.

Use the guidance for this exact file and edition. Where a setting is not specified, check the print instructions or ask for help before printing.

Download this file ↓

03-wheel-screw.stl

Print settings

Orientation: Supplied flat underside on the bed; keep any component regions aligned.
Layer height: Not specified for this file.
Supports: Not specified for this file.
Material: Not specified for this file.
Nozzle: Not specified for this file.
Walls: Not specified for this file.
Infill: Not specified for this file.
Bed adhesion: Not specified for this file.
Scale: 100%, millimetres. Do not scale to fit a bed.
Assembly & finishing: Print one set. Do not split aligned book/grille regions. Game-specific middle rings and their assembly directions come with the relevant games. Keep coatings out of hinges, threads and openings.
Print testing: Digital geometry checks passed. A fresh slice and exact-edition physical print, fit, movement, legibility and wear checks remain unverified.

Use the guidance for this exact file and edition. Where a setting is not specified, check the print instructions or ask for help before printing.

Download this file ↓

04-wheel-centre-retainer.stl

Print one decorative centre at 100% in millimetres, flat reverse on the bed. The underside lettering has 0.35 mm-wide, 0.30 mm-deep outside outlines; letter faces stay flat. The top decoration and fitting geometry are unchanged. Use your own printer profile, inspect the grooves in a fresh slice and test seating and free rotation. If you already printed the Codex kit, only this part needs reprinting. Do not stack it with a game-specific replacement centre. Digital checks and download approval do not establish physical fit or print quality.

Print settings

Orientation: Flat reverse on the bed, decorated face up.
Layer height: Not specified for this file.
Supports: Not specified for this file.
Material: Not specified for this file.
Nozzle: Not specified for this file.
Walls: Not specified for this file.
Infill: Not specified for this file.
Bed adhesion: Not specified for this file.
Scale: 100%, millimetres. Do not scale to fit a bed.
Assembly & finishing: One connected decorative centre. Reprint only this part when upgrading an existing kit. Check seating/free rotation; do not stack with a game-specific replacement centre.
Print testing: Digitally checked and approved for download on 27 September 2026. No physical test of this outlined edition reported.

Use the guidance for this exact file and edition. Where a setting is not specified, check the print instructions or ask for help before printing.

Download this file ↓

05-ruler.stl

Print settings

Orientation: Supplied flat underside on the bed; keep any component regions aligned.
Layer height: Not specified for this file.
Supports: Not specified for this file.
Material: Not specified for this file.
Nozzle: Not specified for this file.
Walls: Not specified for this file.
Infill: Not specified for this file.
Bed adhesion: Not specified for this file.
Scale: 100%, millimetres. Do not scale to fit a bed.
Assembly & finishing: Print one set. Do not split aligned book/grille regions. Game-specific middle rings and their assembly directions come with the relevant games. Keep coatings out of hinges, threads and openings.
Print testing: Digital geometry checks passed. A fresh slice and exact-edition physical print, fit, movement, legibility and wear checks remain unverified.

Use the guidance for this exact file and edition. Where a setting is not specified, check the print instructions or ask for help before printing.

Download this file ↓

06-grille-engraved-portable-single-colour.3mf

Portable 3MF geometry only. Keep both aligned regions as ONE object using ONE filament. Markings formerly defined by colour are engraved 0.30 mm. Use the supplied flat underside; optional paint must not fill markings or openings. Use your own printer profile.

Print settings

Orientation: Supplied flat underside on the bed; keep any component regions aligned.
Layer height: Not specified for this file.
Supports: Not specified for this file.
Material: Not specified for this file.
Nozzle: Not specified for this file.
Walls: Not specified for this file.
Infill: Not specified for this file.
Bed adhesion: Not specified for this file.
Scale: 100%, millimetres. Do not scale to fit a bed.
Assembly & finishing: Print one set. Do not split aligned book/grille regions. Game-specific middle rings and their assembly directions come with the relevant games. Keep coatings out of hinges, threads and openings.
Print testing: Digital geometry checks passed. A fresh slice and exact-edition physical print, fit, movement, legibility and wear checks remain unverified.

Use the guidance for this exact file and edition. Where a setting is not specified, check the print instructions or ask for help before printing.

Download this file ↓

Multicolour printing guidance

codex-and-objects-multicolour.3mf

Open as a two-plate project in a compatible slicer. This is the approved Finished project, including the lettered decorative wheel centre, with all geometry, colours, layout and saved settings unchanged. Saved Flashforge Creator 5 Pro / 0.4 mm nozzle / Generic PLA settings: 0.20 mm layers, 0.25 mm first layer, three walls, 10% infill; supports and brim off. Check your actual printer/material and slice again; no G-code is included. Keep book components aligned and retain the upright book pose. Use the separate single-colour edition for a one-filament print. Print one set, not both editions. Game-specific middle wheel rings are supplied separately with their games. Exact-file integrity, archive and digital geometry checks passed. A fresh slice and exact-edition physical fit, movement, legibility and wear checks remain required.

Print settings

Orientation: Retain the supplied two-plate layout and upright book pose.
Layer height: Saved 0.20 mm; first layer 0.25 mm.
Supports: Saved off; inspect bridges and overhangs in a fresh slice.
Material: Saved Generic PLA; check your actual material.
Nozzle: Saved 0.4 mm; verify your actual printer.
Walls: Saved three walls.
Infill: Saved 10%.
Bed adhesion: Saved textured PEI and brim off; check first-layer adhesion.
Scale: 100%, millimetres. Do not scale to fit a bed.
Assembly & finishing: Print one set. Do not split aligned book/grille regions. Game-specific middle rings and their assembly directions come with the relevant games. Keep coatings out of hinges, threads and openings.
Print testing: Digital geometry checks passed. A fresh slice and exact-edition physical print, fit, movement, legibility and wear checks remain unverified.

Use the guidance for this exact file and edition. Where a setting is not specified, check the print instructions or ask for help before printing.

Download this file ↓

Before printing.

Use the files and guidance for the exact released edition. Single-colour and multicolour choices, layer height, supports, material and orientation will be stated with each file. Do not print unreleased parts or assume a model is a complete tested kit.

No printer? Find a workshop →