"One Must Die" by Candice Pedraza Yamnitz, Amber Lambda, Sarah Everest, Claire Kohler, Lydia Mae, and C. C. Urie

I'm not sure I've ever read a novel co-written by six people before.  Not an anthology, but a single novel!  It's quite the ambitious endeavor, but I think it worked really well.
It's hard to describe One Must Die succinctly.  As the cover says, it's a steampunk murder mystery.  Set in a mansion floating above earth that's filled with robots.  And hidden keys.  And secret passageways.  And, somewhere, a treasure vault.
A whole bunch of strangers are invited to try solving a mystery and finding the...