itch.io

Get the bombs from the clean sewers via the entrance in the mafia hideout in Nightless city. You can get in there after starting the maid questline either by fighting your way through to the Don and getting free reign of the place that way, or by posing as an employee using the bunny suit if you know where that is. If I remember correctly, I think the bunny outfit is accessible via the mafia hideout in Old Town, which you appear to have already found judging by the screenshot.