For fans of unexpected-yet-badass female sleuths, meet former FBI agent-turned-boardinghouse landlady Ethel Fiona Crestwater. Her age affords her precious invisibility. She can outthink and outshoot most men—and women—half her age.

When someone murders one of her boarders, Ethel springs into action—much to the surprise of her double-first-cousin-twice-removed, Jesse, who has recently come to stay with her while he attends university. As he watches her photograph the crime scene, conceal evidence, and speed-dial the Secret Service Director, Jesse realizes that there's much more to Ethel than appearances suggest.

When Jesse is assaulted and the gym bag full of cash Ethel had hidden is stolen from the basement, the pair decides it's time to launch their own unofficial investigation. With no one to trust but each other, this unlikely duo learns that the only thing truly worth risking your life for is family.