We're here to kill Lady Boyle, the lover of one of the game's main antagonists. The problem is, there are three Lady Boyles at the party. We don't know our target's first name, and the three sisters are all wearing matching, but differently coloured, masks. We have to do some detective work. Cleverly, every time you play this mission, the target's name and mask colour will be randomised, so don't worry about us spoiling anything.
In a shadowy drawing room lit by a flickering fireplace, a partygoer in a scarecrow mask stops us. He says he knows what we're here for, and begs us not to kill Lady Boyle. In doing so he reveals her first name, Esma. He's madly in love with her, and promises she'll never been seen again if we get her to the house's basement unharmed.
Now we have a name, and a way to get rid of the target without killing her. But we still don't know what colour costume she's wearing. Small tasks, like fetching a flirtatious woman a drink, will reveal clues about the correct sister's identity, but we try something a little more daring.
We leave the warmth of the party and slip into the courtyard outside. Fireworks blaze in the night sky as guards pace the perimeter. Using Blink - a short-range teleport - we spirit up the side of a nearby tenement block, then hop over to one of the mansion's first floor balconies. A lone guard is stationed here, but we knock him out with a sleep dart and hide his body.
If anyone spots us up here the guards will be alerted. We peek through keyholes to keep track of their patrols, creeping between bedrooms. In one we find a diary on a bedside table. It's Esma's, and reveals that her costume is red, which gives us everything we need to fulfil our contract.
Using Blink, we teleport back down to street level and rejoin the party. Your mana meter has to be topped up with potions to use more elaborate powers, like possessing enemies or summoning swarms of vicious rats, but you'll always have enough to teleport - albeit with a few seconds of regeneration time between each use.
We immediately spot our target in red. We follow her until she stops in an isolated corner of the party. It's a good place to knock her out, but we'd never get the body to the basement unnoticed. As well as sword- wielding royal guards, there are Overseers protecting the guests. Their unnerving gold masks are locked in a tortured grimace, and the wind-up music boxes strapped to their chests block your powers as they grind out their grim tune.
Instead, we talk to her. We tell her that she's marked for death, and that she has only one way to escape with her life intact: her mystery suitor, the scarecrow. Dialogue trees branch in different directions, and we could have easily picked the wrong option and frozen this means of finishing the mission. Luckily, we don't, and she agrees to meet us in the basement.