Watchlist, by Jeffrey Deaver, et al

It turns out that mystery and suspense writers talk with each other.   In particular, through the association called International Thriller Writers.   In this book, 15 writers (such as Lee Child, Joseph Finder, Lisa Scottoline, and Jeffery Deaver) collaborated to build a double-novel set around the same main character (hero Harry Middleton).

This turned out to be a very successful venture.   The book is very good -- absolutely perfect for a couple of airplane trips.