A Talent for Murder - Peter Swanson

Martha, a librarian, marries Alan, a charming salesman often away for work. When she discovers a suspicious bloodstain on his shirt from a conference, Martha investigates Alan's travels, uncovering five unsolved murders. Unsure if Alan is a killer or if it's coincidence, she seeks advice from her friend Lily. Lily uncovers truths, leading to a twisty and clever exploration of deception and danger.