The Flask of Quicksilver is one of four materials Coen needs for the Arbiter armour set, and it is the fiddliest of the group. It is not hidden in a chest or dropped by an enemy. It sits in plain sight on a table at the very top of a tower in the south of The Silts, behind a door the game refuses to let you open until a specific quest is out of the way.
Quick answer: Climb to the top floor of the tower in the south of The Silts and take the yellow flask off the table inside the ritual room. The door only opens after you complete the Home Sweet Home quest. If you would rather skip the climb, the Alchemist Vendor in Svartrau City keeps one in stock for around 4,000 denarii.
What the Flask of Quicksilver is used for
The flask is a quest item with no combat or crafting use of its own. It exists to satisfy the objective “Find a flask of quicksilver” in the side quest A Bulwark Against Darkness, which starts when a stranger hands Coen a letter and a list of armour components after you hit Infamy Level 4.
Picking it up is not gated behind the quest itself. You can grab the flask long before the letter reaches you, and the objective ticks off automatically once you read the list. The other three components are a relic of a saint, a bundle of silk threads, and the moult of a large lizard. Hand all four to Nareh, the uriash blacksmith at the Uriashi Hermitage in the northwest, and the ritual that produces the Enhanced Arbiter armour set can begin.
Finish Home Sweet Home before you can take the flask
Walking up to the tower early does nothing useful. Interacting with the door on the top floor costs 4 time segments and drops Coen straight into a flashback of the prologue rather than into the room with the flask. That flashback is the Home Sweet Home quest, and it has to be finished before the room becomes accessible.
The sequence runs through a fight, a Gargoyle boss, and a stretch where you inspect a well in Focus Mode and escape through a cave into a church. Inside the church you help the priest piece events together by interacting with people in this order: Alin, then Esme, then Coen. That opens a locked door leading to another portal. Inspect the red glowing tree stump, clawride down to the river, and finish the conversation. Coen wakes up at the bottom of the tower.
Tip: Go straight back up after the quest ends. The flask does not disappear if you leave, but the tower is a long detour to repeat, and the time segments spent travelling there are real.
Flask of Quicksilver location: The tower in southern Vallis Sanguina
The tower stands in the forested southern stretch of The Silts, south of the Turtle Rock Shrine. It is tall and hard to mistake for anything else once you are close, with wooden staircases wrapped around the outside.
Buying the Flask of Quicksilver from the Svartrau City alchemist
There is a purchase route if the tower is inconvenient or you handed off your first flask. The Alchemist Vendor in Svartrau City carries one permanently, and the stock refreshes rather than running dry. Expect to pay roughly 4,000 denarii, which is the item’s own listed value.
| Route | Where | What it costs you |
|---|---|---|
| Tower pickup | Top-floor room, tower in southern The Silts | Free, but Home Sweet Home must be complete (the door costs 4 time segments) |
| Alchemist Vendor | Svartrau City, always in stock | Around 4,000 denarii |
How to confirm the pickup worked
Two things happen the moment you take it. A “Flask of Quicksilver (1)” notification appears on screen, and if A Bulwark Against Darkness is already active you get a QUEST UPDATED banner with “Find a flask of quicksilver” struck off in the journal. Open the Journal menu and check the objective list under the quest to be certain.
If you picked the flask up before the letter arrived, nothing will tick off yet. That is expected. Read the mysterious letter and then the list of armour components in the Books & Notes tab of your inventory, and the objective resolves immediately using the flask already sitting in your bag.
Why the flask is not on the table
There are only two reasons the room comes up empty. Either Home Sweet Home is unfinished, in which case interacting with the door pulls you into the prologue flashback instead of the ritual room, or you already collected the flask on an earlier visit and it is sitting in your inventory as a quest item with an orange background.
Once the flask is secured, the remaining components can be gathered in any order, and Nareh accepts them one at a time. Each delivery hands back an Arbiter armour piece straight away, so there is no reason to sit on the quicksilver until the full set of four is ready.
