While Ivar has been being deprogrammed, Mela has been looking for him. She needs him to help the group with a job... naturally, he agrees. Sasha and Lucia follow along as he heads out into the swamp with Mela. They meet a couple of the thugs from the shack, and set to offloading a small boat, taking the barrels on board to a long, low building out in the swamp that turns out to be where the soap maker Lucia met earlier made his soap.
It's made, because while sneaking up to this building Sasha falls onto his dead body out in the bushes. He seems to have been stabbed to death.
Ivar and the others load some barrels of liquid and a couple of barrels that seem to contain something like sand or grain and then they're done for the evening. Mela tells Ivar that they'll need more help doing some mixing in the week to come. After they leave Sasha and Lucia check the place out, finding a couple big soap-making vats and various supplies. They manage to find their way out of the swamp only slightly attacked by leeches, and go have a bath.
Meanwhile Baba and Gaius have been keeping an eye on the drops in the burial ground, and poking through various trees find a set of papers in oil-skin. They copy them in the dark using the copy slates, and later discover them to be instructions for putting together and firing a small catapult, clearly intended for the non-siege-engineer.
The coming days bring more surveillance. Sasha follows a new man who leaves something in one of the drops, but despite the ridiculousness of the mysterious cloak he is wearing he loses her when he gets back to the city. Ivar goes back to stir - the oil and other agents are being mixed in the vats while heated, with strict instructions not to let it get too hot. Everyone there is happy to have big strong Ivar helping with the stirring.
The materials left in one of the drops by the mysterious cloaked man are ten little vials. Inside is some powder topped with some sort of oil... scooping out a little of the powder, Baba discovers that it ignites in air! She makes up look-alike replacement vials and those are left in the drop.
Where they are picked up by the well-voiced man who takes them to the soap factory and delivers them with grave warnings about how dangerous they are. He then heads back to the city, where Sasha ends up looking in his window just as he is drawing the curtain. She runs off quickly and does the rest of her surveillance in various disguises... including following him around the next day with Lucia's help as he goes and looks at almost all the prayer mills in the city, minus the one to Yaifestia, the wife of Danadar and general Daran fertility goddess.