Suggest a book that’s a more adult version of the 39 clues

Hello, I was reviewing my old books to donate and came across the 39 clues series and I remember how much I was obsessed with them as a kid and wanting to solve the mystery. I do feel though if I read it again it might feel childish and I don’t want to ruin the memories associated with it so is there a more adult version of that kind of mystery book? Thank you