"That is the book which can summon the ancient being who will burn the world for seven days.
There written a secret sorcery to give one eternal life and power.
It will be a big shame to not introduce grimoire of dark plague!"
"So every books here are forbidden to be read or open?"
"Of course! We are not idiots to let anyone learn dangerous art of magic, putting books in the open library and making anyone just literally take it without disturbance.
These are protected with five-fold seal of ring fire, and it will destroy them when the conjurer, myself die in accident or killed."