Graveyard Keeper 2 Necronomicon

The Donkey starts it near the Morgue, after Agatha's corpse-delivery conversation. It points you to Gunter in the Astrologer's Tower.

At 20 reputation Gunter will talk about the Necronomicon, but he does not give it yet — that conversation only opens the next objective.

Three +10 sources get you there: returning Gunter's Tarot Cards, completing the test ceremony in Congregation Trouble, and delivering 1 Printed Poetry.

The test ceremony also starts the quest Rhyme and Printed, which is where the Printed Poetry recipe comes from.

Printed Poetry is made at the Printing Press, which the Newspaper technology unlocks.

The recipe is 1 Blank Softcover Notebook, 2 Ink and 1 Story of gold quality. Notebooks and Ink come from the Writing Desk.

The gold-quality Story is the slow part, so start writing stories early.

Ask Gunter again at 30 reputation to receive the Necronomicon, 10 more Gunter reputation and a silver-quality Story.

It unlocks the Reanimation Liquid technology and the Forbidden Knowledge achievement ("Some books should stay buried").

The Necronomicon is part of the Resurrection Lab route, but it does not raise zombies on its own. You also need the room, a suitable body, a collar, Faith, Reanimation Liquid and a powered device.

It stacks to 1, cannot be destroyed and no trader buys it.

Study it: 50 Science for 300 blue tech points over 16 ticks, and you keep the book afterwards.