Overview
Whatsoever a Man Soweth… is the final main quest of Hearts of Stone. With Olgierd’s three wishes granted, Gaunter O’Dimm is ready to collect his due, and Geralt has to decide whether to save Olgierd von Everec from him.
O’Dimm at The Alchemy
When Geralt arrives at The Alchemy to meet Olgierd’s man, O’Dimm is waiting. When a drunk interrupts, O’Dimm stops time. He tells Geralt to bring Olgierd to the Temple of Lilvani to complete their contract, and kills the drunk for interrupting before he leaves. Olgierd’s man also passes on that Shani wants to see Geralt.
Professor Shakeslock
Seeing Shani is optional, but it is the only way to challenge O’Dimm later. She is leaving for the front as a field medic, but she has found someone who may know more: Professor Premethine Shakeslock at the Oxenfurt Academy. She helps Geralt get into the grounds. After a fight with witch hunters, Geralt blasts his way into the professor’s locked house with Aard, damaging its beams.
The blind professor stays inside a protective circle. He reveals that Olgierd once had to choose between losing Iris and losing Vlodimir, which cost his brother his life. And he explains how O’Dimm can be beaten: challenge him to a contest of wits, with the only thing he truly wants, a soul, as the stake. Then a weakened beam gives way, the professor stumbles out of his circle and dies. After this, Geralt can say a final goodbye to Shani.
On the moon
The Temple of Lilvani is reached through caves east of Toderas. Geralt hands Olgierd the rose or the painting, fulfilling the last wish. O’Dimm declares the contract complete. Olgierd objects that the final meeting was to take place on the moon, and O’Dimm simply blows the dust away from a mosaic of the moon in the floor.
The choice
Let O’Dimm take Olgierd. O’Dimm claims his soul and offers Geralt a reward: the Caparison of Lament, the Horn of Plenty, a bottomless carafe of vodka, or a fortune in crowns. Geralt can refuse all of them. If Geralt asks for help finding Ciri, O’Dimm says that is beyond him, but offers advice for a better ending with her (only before The Isle of Mists, or in a standalone expansion playthrough).
Challenge O’Dimm. Only possible if Geralt met Shakeslock. Both souls are staked, and O’Dimm sets a riddle in a strange, twisted world full of decoys, specters and mirrors, with time running out. The answer is glass that can’t be broken: a dry fountain behind the house, whose cracked wall Aard can open. On the way, the Viper venomous silver sword can be pulled from a stone. If Geralt wins, O’Dimm loses his claim and both men go free, and Olgierd gives Geralt his sword, Iris.