For the golden gate beneath the upper tower stairs, published player reports say the slot accepts a book without requiring one particular title. This is a community-reported interaction, not a developer-confirmed rule. Returning lost books and cleaning the tower are separate objectives with their own achievements.
Which book puzzle are you facing?
“Book puzzle” can mean the golden gate’s slot, the lost-book collection, Wourha’s research or simply a blocked part of the library route. Start by identifying the actual object in front of you. A row of seven numbered statues needs the gargoyle solution, not a book.
If you have just collected the Storm Gem and are stuck at nearby doors, check the lower switch and staircase route. That progression leads to Budaen and the Archives Key. Searching shelves for a missing title will not replace that key requirement.
Golden gate under the stairs
The launch-week puzzle reference records Steam players using a book in the slot at the gate beneath the last-floor staircase. The report says the specific title was not important and that the book could be removed afterward. One reported example is The End of Epha.
Because the underlying community thread is not preserved as a stable, specific citation in the available reference, treat the general “any book” claim with caution. Save before testing the interaction and confirm the in-game prompt. This guide does not turn a reported example into a requirement to find that exact title.
Lost books are a collection objective
Steam’s official achievement list separately confirms I’m Not Paying the Late Fee, which concerns returning the lost books. The existence of that achievement does not provide a complete set of book coordinates or prove that a particular optional gate is mandatory for every book.
Look for interactable books among the tower’s ordinary props and side rooms. The distinction between scenery and an inventory pickup matters here. Check the interaction prompt rather than assuming every visible book can be taken, and keep track of rooms you have already searched.
Cleanup is another task
Sparkling Clean is the official achievement associated with cleaning the Tower of Knowledge. Published puzzle notes discuss post-Necronomicon exploration and a route from the pitfall-room stair area toward a wall beyond bookcases.
That movement clue is also player-reported. It is not a complete cleanup route, and this page does not claim that crossing one hidden entrance completes the achievement. After the boss, use newly available tools to recheck previously blocked passages and compare your current objective with the in-game description.
Keep a useful record
If you are investigating a missing book, record its displayed name, floor and the nearest recognizable staircase, monument or doorway. A screenshot of the pickup prompt is more useful than a screenshot of an entire shelf without a label. Save after collecting something you want to retain.
The achievement checklist can track your own progress, but its local ticks do not connect to Steam. No complete lost-book location list is claimed in this edition. We would rather keep that boundary visible than invent a final shelf to finish a table.
Sources and scope
Reviewed November 5, 2026. Interaction reports come from the published puzzle reference and its source notes. Objective names are checked against Steam’s official achievement list. The generic Steam discussion index does not independently verify the gate behavior; that part remains explicitly player-reported.