"Thirty-three-year-old Abby Stern has made it to a happy place. True, she still has gig jobs instead of a career, and the apartment where she's lived since college still looks like she's just moved in. But she's got good friends, her bike, and her bicycling club. She's at peace with her plus-size body--at least, most of the time--and she's on track to marry Mark Medoff, her childhood summer sweetheart, a man she met at the weight-loss camp that her...

To celebrate her birthday, George is taking Nancy and Bess on a bike tour around Mystic Lake, but when their tour guide disappears and unknown adversaries steal their supplies and slash their tires, Nancy begins looking for clues.