Even if it is not necessary to successfully complete it, or leave it uncompleted (the quest will automatically fail at the end of the Chapter), it is connected with a primary quest, Royal Blood.
During the quest Royal Blood, you have to gather evidence which will help you judge Prince Stennis. This quest is automatically received if you talk to the human peasantry in the middle of the conflict, in the Castle of the Three Fathers in Vergen.
You are told that a suspect peasant, Willy Oblate, is now guarded by some Scoia'tael and he may have something interesting to tell. You find him outside down the hill from Earso, a few steps to the west of Vergen jail. He is reticent to talk, but after you either intimidate him, or use Axii sign hex, he tells you that he overheard a suspicious conversation between the Prince and the priest Olcan. Then he points out to the priest's house to find more clues, but to locate it you need to talk to the alderman. So talk to Cecil Burdon, and then go to Olcan's house, to the south of Rhundurin Square. Searching in the room (you can activate the Witcher medallion to highlight relevant items) there are Olcan's notes, a sort of schematic for a carved goblet, the same described in Suspect: Thorak quest.
After you find and open Thorak's locker, you also find Olcan's receipt and both Suspect: Thorak and this quest are completed. You also receive 1000 XP. Note: this quest may fail if you have not completed it in the right order. Before heading to Thorak's house, it is suggested to do Baltimore's Nightmare quest first and deal with Thorak. If you decide to kill the dwarf, you can loot the key from his remains that opens a chest inside his house.
- If you want to Support the Prince (fair trial) and complete "The Walls have Ears", do not complete Baltimore's Nightmare quest, talking to Cecil Burdon. Stop at the point when you have to either kill or spare Thorak. Then, in Royal Blood, when the riots arise, start questioning for opinions talking only to the peasants and the dwarf. Ask him about possible duplicate goblets. The dwarf will point you out to another runic master smith, Thorak, activating Suspect: Thorak quest. When the journal quest says "Wait for events to unfold", complete Baltimore's Nightmare quest, talking with the alderman. Now you can complete both Suspect: Thorak and The Walls Have Ears opening Thorak's locker in his house.
- Here the few steps to complete these four quests are listed, as already described above:
- After the riot breaks out (Royal Blood quest), talk to only the dwarves and peasants.
- Leave the riot and proceed to complete The Walls Have Ears until it reads "Wait for events to unfold."
- Proceed to complete Suspect: Thorak until it reads "Wait for events to unfold."
- Proceed to complete Baltimore's Nightmare until you kill Thorak.
- Finish Suspect: Thorak. Opening Thorak's chest should complete both quests.
- Walk to Cecil's home and finish Baltimore's Nightmare.
- Return to the riot and complete the scene based on the evidence you have gathered.
This procedure will allow you to complete both sub-quests and maximize experience as well as reveal the maximum amount of evidence. However, since you can only talk to two parties, this means you will be unable to hex the guards to Stennis's room and converse with him. If you would like to see what Stennis has to say (or any other non-essential party), make a save before talking to anyone at the riot, talk to Stennis (or other non-essential people), the reload the game. He does not provide any hard evidence to prove his guilt or innocence.
- A bug occurs if you found Willy Oblate by yourself, before talking to the human peasantry in the Castle of the Three Fathers. You will not be able to talk to him again, your quest objective will be stuck at talking to Willy Oblate. Simply run back and talk to the guards outside the door to try to talk to Prince Stennis. This will mean that you will be unable to have this quest as 'finished' in the quest screen.
- You can solve this bug by going to the human enclave (near the main gate where the priest condones you), entering the house to your right and looting Olcan's Notes. It will then show on your quest log "Wait for events to unfold.".
- You may remember that Geralt had been trying to ascertain who had poisoned Saskia the Dragonslayer. One trail led him to a serf who had easy access to Saskia's chambers and could have been bribed by the assassins. Well, the Scoia'tael had been shadowing him closely. They were merely waiting for him to reveal his treachery. Iorveth was receiving reports of his every move.
- The servant from Saskia's quarters implicated the priest named Olcan as someone who could have been involved in Saskia's poisoning. Though the priest was already dead, having suffered a memorable accident on the cursed battlefield, his home could still be searched. Since the alderman Cecil Burdon knew everyone in Vergen, the witcher went to ask him where the divine servant had lived.
- Our detective with the wolf medallion around his neck finally learned where Reverend Olcan had lived. So he went to search the priest's room.
- In Olcan's room, Geralt found a set of designs for a goblet identical to the one Saskia had used during the council. The designs clearly implicated Olcan as an accessory to Saskia's poisoning, yet they did not solve the mystery as a whole. Geralt's investigation was still open, so he decided to continue his search for clues. He went to talk to Vergen's inhabitants.
If the quest fails:
- Since Saskia was dying and time was of the essence, the witcher had to drop the sluggish thread of the goblet and concentrate on the mystery's other aspects.