Mouth to Mouth (by Antoine Wilson)

This would make a great book club book - it's a compelling read, and under 200 pages, but explores a narrative within a narrative that holds some surprises.  Plus it's a Tournament of Books book!  

The conceit is that our narrator is in an airport and runs into an old friend named Jeff. Their flight is delayed, and Jeff decides to tell him his life story and his biggest secret, all stemming from his rescuing a man who was drowning decades before.

Our narrator doesn't just stay out of the story - he asks questions, comments on Jeff's story, and occasionally steps away to think about what he has heard. I loved this, plus the setting of an airport lounge (and Jeff's takes of working at an art gallery).  I can't wait to discuss this one in the ToB (here's hoping they have comments again instead of trying to host it on Discord, which was miserable).