Killers of a Certain Age by Deanna Raybourn

Billie, Helen, Mary Alice, and Natalie are female assassins who have worked for forty years for an organization called The Museum. While on a cruise celebrating their retirement, the four women realize that someone is trying to kill them. Soon, they discover that it's coming from The Museum. The friends then do some investigating of their own to find out who wants them dead and know that the only way to be free is to eliminate the threat. Killers of a Certain Age is a fast-paced read with lots of action, snappy dialogue, and engaging characters that I hope to see again. It will be published in September.