Ancient Circles of Vale Sangora: How to Get the Mercurial Fervour Manual

Thirteen Ancient Circles are scattered across Vale Sangora in The Blood of Dawnwalker, and each one works the same way: wake the stones, survive what answers, take the loot. The circle in the Northern Swamps is the one worth prioritising early, because its chest holds the Mercurial Fervour Manual — the unlock for a Witchcraft passive that makes daytime travel noticeably faster.

Quick answer: Travel during the day to the Ancient Circle north of Briar Sloughs Crossing in the Briar Sloughs, hold Focus at the glowing altar to cast Astral Communion (this spends 1 Time Segment), kill the summoned spirits, then loot the chest and the nearby cache for the Mercurial Fervour Manual, the Potent Revitalizing Tonic recipe, and Red Darksteel Bracers.

What you need before starting the Northern Swamps circle

Ancient Circles are a daytime-only activity. The ritual runs on Astral Communion, a Witchcraft skill Coen can only use as a human, so arriving after dark means the altar simply will not respond. Unlock Astral Communion in the Witchcraft tree first, or the trip is wasted.

Two more things to sort before you interact with anything. Starting the trial consumes 1 Time Segment, so factor that into whatever else you planned for the day. And check your quick-use slots — healing items rather than food, because the fight begins the instant the ritual lands and there is no shopping break in between.

Ancient Circle location in Briar Sloughs

The site is marked on the map as an Ancient Circle and sits just north of Briar Sloughs Crossing, in the northern swamp belt of the valley. You are looking for a cluster of standing stones in open marshland, with a large slab carrying a faded red fresco at its centre. Inspecting the fresco — the snake symbol and the tears in the air around it — logs the Ancient Circles of Vale Sangora objective if it is not already active.

Quest Updated banner showing the Ancient Circles of Vale Sangora objective at the standing stones — The Ancient Circles of Vale Sangora objective updates once you inspect the fresco at the circle. Image: Rebel Wolves

How to trigger the ritual and win the fight

Hold the Focus button while standing inside the circle. A glowing yellow magic source appears on one of the low stone altars — that is your interaction point, and it is only visible through Focus.

Interact with the magic source to cast Astral Communion. The Time Segment is spent here, and the summoning is immediate, so do not do this with a sliver of health left over from the walk in.

Fight the spirits the ritual pulls through. Four hostile astral entities spawn at this circle, and across the valley these trials throw Vidmos, Psoglavs and Guardians at you. They arrive together rather than in waves.

Coen with sword drawn facing summoned spirits in the Briar Sloughs marshland — The summoned spirits appear all at once around the stones in the Briar Sloughs. Image: Rebel Wolves

Lock onto one target at a time and back out of the middle of the circle. Enemies that surround you inside the stones will hit from angles you cannot see, and the open marsh on the edges gives you room to reposition between swings.

Locked-on enemy marked with a diamond icon and health bar during the Ancient Circle fight — Focus on one marked target at a time rather than swinging into the group. Image: Rebel Wolves

With the last spirit down, loot the chest that the trial leaves behind, then sweep the immediate area with Focus for a second hidden cache. Both need to be opened — the manual and the recipe are not all in the same container.

Loot window listing a Vial of Aether with Loot All and Cancel options — Use Loot All on both the chest and the hidden cache so nothing is left behind. Image: Rebel Wolves

Northern Swamps Ancient Circle rewards

Reward	What it does
Mercurial Fervour Manual	Makes the Mercurial Fervour Witchcraft ability available to learn
Potent Revitalizing Tonic (recipe)	Adds the tonic to your crafting list
Red Darksteel Bracers	Epic bracers

Note: if you miss this circle or want a spare, the Mercurial Fervour Manual also turns up at the Ancient Circle east of Maragir, alongside a Tempered Long Basilard. The Red Darksteel Bracers repeat at the Silts Overgrowth circle.

What Mercurial Fervour actually gives you

Mercurial Fervour is a passive Witchcraft ability with a day-only restriction. It grants Haste during exploration by slowing the world around Coen, and it does not occupy a common slot in the Active Abilities panel, so keeping it on costs you nothing elsewhere. It caps at level 4.

Level	Effect
1	Gain Haste
2	Haste costs 50% less Stamina
3	Haste costs 50% less Stamina and is 20% faster
4	Haste costs no Stamina and is 20% faster

Picking up the manual does not switch the ability on. Read it, then open the Witchcraft tab on the character screen and invest in Mercurial Fervour there — it stays greyed out as unavailable until the manual has been used.

Witchcraft tab on the character screen with Mercurial Fervour selected and its effects listed — Mercurial Fervour appears in the Witchcraft tab once the manual has been read. Image: Rebel Wolves

Why the altar will not activate

There are only a couple of reasons the ritual refuses to start. It is night, and Astral Communion is unavailable to Coen in vampire form. Or the skill has not been unlocked in the Witchcraft tree yet, in which case the glowing source shows under Focus but there is nothing to cast at it.

You will know the circle is finished when the spirits stop respawning and the chest becomes lootable. Ancient Circles are one-and-done per location — the same site cannot be farmed for a second manual, so the only way to collect more copies is to work through the remaining twelve circles in the valley.