There's a new face in Sleepyside, and Trixie Belden is sure this stranger is up to no good. Too bad no one else believes her. But if anyone get can to the truth of this visitor's true motives, it's detective Trixie!

Trixie Belden hasn’t talked to Diana Lynch in a long time—not since her family got incredibly rich…and snobby. But when Trixie and her best friend, Honey, spot Diana looking a little down, Trixie knows it is time to put old grievances in the past.

Except the past is exactly the problem for Diana. Her long-lost uncle Monty has recently arrived from Arizona, and Diana is less than thrilled about the reunion. Monty insists on hosting lavish parties, he won’t stop pulling pranks, and he embarrasses Diana in front of all of her friends.

Trixie isn’t charmed either. Monty may have fooled all of the adults, but his timing seems too good to be true. But can Trixie prove Uncle Monty is an imposter—or will Di be the one sent packing?