This is the last Lodger room we'll see in this chapter, and it belongs to Mr.s Helsby, Ito and Chestro. We haven't met Chestro yet--there are about 20 Lodgers in total, and not all of them will be introduced in this sequence. There are more important introductions* to hit first. . . .
This is a much larger laboratory than average, and most of what we'll see belongs to Mr. Helsby. He is an "exploratory bathynaut," which, like Bryson's aeronaut, was basically a real thing. Bathyspheres were early deep-sea submarines, which you can learn about in this excellent 99% Invisible episode. Helsby also deals in stranger vehicles, like diving bells and the underwater ship that his assistant is working on in the background. By the way, Helsby is basically this universe's version of Captain Nemo, just a bit younger and not gone entirely rogue yet.
This week we've also got the last of the Bleeding Heart Kickstarter cameos, but I'm going to hold off on that until next week to offer a proper backstory to what the heck is going on with him!
*and plot points! gosh!