The book

Your own copy of the Inferno, and not a magic object. You take it in Limbo, resting on a worn slab among Homer, Horace, Ovid and Lucan, with a short lamp over it half a metre across: in a place where nobody suffers, the only thing you find is the thing that gives light. The four of them stand seventy two degrees apart and the fifth place in the circle is empty, facing the gate; that is the place you go and stand in.

It is the same thing this wiki is for whoever reads it. It tells you where you are, what the thing in front of you is and what has already been written about it before you got here, and it never tells you how to get past. The difference is that Dante is the one holding the book, and you are the one holding the wiki.

After Limbo the object itself is finished, and the code says as much: the names you collect go not into the book but into the notebook, on the page that stays open, and those names are the game’s real currency. The book remains the reason they count for anything: it is the text in which these dead have already been named once. The line the game shows over the slab says it is a stone among the four, worn where things are set down, and that in a place where nobody suffers the only thing left to do is read.