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One of the books needed for the quest, "Hyperagonal Media Theorem", is carried by Rilvin Dral. After a certain point in the House Telvanni questline, Dral disappears to his pocket realm which is unreachable, taking the book with him. The quest cannot be completed in that case.
Asking around about the book using its topic, people tell you: "I've certainly never heard of a book like that. Sounds like the sort of thing you'd find in Lord Dral's library.", but as far as I could tell from looking around and checking the CS, the book is not placed anywhere.
There should either be a way to continue the quest by finding the book somewhere in Tel Thenim, or getting it from Rilvin Dral's Mouth, or a way to fail the quest by telling Ralam Othravel that the book is nowhere to be found.