They All Fall Down by Rachel Howzell Hall
After a difficult confrontation, Miriam enters a reality show contest to win money, fix her life, and prove to her daughter that she is a mother to be proud of. Except, before she reaches the remote island where the show takes place, but after it's too late to turn back, she learns that there is no reality show. Miriam has been duped into spending the weekend on an island with six other strangers and no way to contact the mainland. Then people start dying. It takes quite a while (about a third of the book) before the first body falls, but once that happens, the book is off to the races. It becomes rapidly obvious that everyone on the island is terrible - living embodiments of the seven deadly sins and they are being punished for the crimes by... someone... I noticed a number of other reviewers struggled with this book and I can see why. There is a dark humour component to the story that doesn't always land, and since everybody is a terrible person, it's hard to root for any