The Leg-Taker of Martira Bay

Hook

Martira Bay’s guards are searching for someone called Jack after new killings in which victims’ legs have been taken.

A charmed gate guard said the watch was looking for “Jack.”
A potion seller said the killer rumors involved people losing their legs.
Guard patrols were visibly heavier than during the party’s earlier visit.
Siv reported that he had heard of the figure and that he eats people’s legs.
Gilos said the guards were failing to solve the killings.
Outside the Rat House, the party destroyed three Boneless and a huge creature formed when rats merged into a single body.
Chanting came from within the Rat House, but the party fled before investigating it.
The rat-swarm creature bit Rage and left an unidentified infection.

Who is Jack?
Is the leg-taking connected to the earlier wererat activity, the city’s rats, or a separate threat?
Are the guard patrols capable of containing the killings?
Who or what was chanting inside the Rat House?
What infection did the rat-swarm creature leave in Rage?

Evade the responding guards, then investigate the Rat House and the source of its chanting.