Micaiah Johnson's The Space Between Worlds
This was one of my favorite books of 2020, and I've had it on my list to read for book club ever since, and I finally made it a pick this month because a companion novel is out in a couple weeks! Anyway, it was JUST as good on a reread, still totally gripping and fun but also really hitting on some complex themes. The protagonist is a young Black woman whose job is to hop between different worlds for research purposes, but she can only travel to worlds where that version of her has died--and she's died on so many worlds. SO much happens in this and it's such a fun but also a GOOD read, can't wait for the followup.