It's June in Connecticut and Melanie has her hands full with her family and Poodles, but when a breeder and exhibitor of Great Danes dies under suspicious circumstances, she also has a big mystery to solve.

After seeing a Great Dane at a dog show, Melanie's son Kevin has become obsessed with the breed. Aunt Peg introduces Melanie and her son to Audrey Kane, a charming older woman who breeds and shows the big dogs.

Aware of Melanie's talent for sleuthing, Audrey asks for her help in finding a missing brooch. She suspects her stepsister Lara. Sam and Melanie are showing their Standard Poodle puppy, Plum, at a dog show where Lara will also be exhibiting her Great Dane. Melanie makes contact with Lara but gets no answers.

When Audrey is found dead in her home, Aunt Peg enlists the help of the local Great Dane Club to foster Audrey's ten dogs, one of whom Melanie takes on. To her surprise, Lara comes to her and asks her to solve her stepsister's murder. From the president of the Great Dane Club to Audrey's dependable dog-sitter—and not ruling out Lara herself—Melanie soon has more suspects than Audrey had Great Danes. With Aunt Peg's assistance, she doggedly pursues the killer . . .