Thylmurk

Body

The tolerance is in the gut and in the mantle, which filters what the others cannot. The Thylem gut is long and slow and built for rot and fibre to begin with, and this line has taken that further than any other: water that would kill a Thylavane in a season is what a Thylmurk works in every day.

The colour is the ground their line came off, as it is in every Thylem. Theirs came off the dark.

Frailty

The cost is the fluke. Standing water breeds a flat pale worm that enters at the foot and lodges in the mantle, and a Thylem with mantle-fluke goes thin, loses colour, and produces mucus that will not seal, which ends its trade before it ends its life. Clean-water lines get it rarely. Sump lines get it constantly, and the Thylmurk carry it almost to a body, and the whole of the Thylavane's insufferable sense of superiority rests on that one parasite.

Pore-block is the other. One breathing pore, high on the left of the back, and anything that covers it ends the Thylem in minutes, and a line that works head-down in filth gets it more than anybody. The Thylmurk have a tool for clearing one another's, carried on the belt, that other lines find disturbing to look at.

Country

Meruk's Bore is theirs: a wet-hold in a mine sump, poor and small and stubborn, standing water and low lamps, and the walls sealed better than any cistern in the world. It is the least of the three named holds by every measure the surface would use and the best sealed by the only measure that matters to a Thylem.

Regard

They are looked down on by their own people. A people governed by the oldest working sealer, whose only crime is breaking a crossed trail and whose only taboo is drying, has otherwise very little internal ranking, and the one line it does rank is this one. The judgement is about the water rather than the work, and the work is better.