First in another formulaic series (``Pet Patrol'') aimed at middle-grade readers. Though Evie's first five business ideas have ended in disaster, she has high hopes for the sixth; she and friend Megan release nine balloons with ads for a pet-care service. They return home to find a boxful of puppies already on the porch and a note asking that they be given away by four that afternoon. Can it be done? Of course—after a few false starts and minor mishaps. A typical assortment of kindly adults and slightly differentiated children comprise the cast, while the antics of the four frisky puppies supply a cupful of humor. Mild entertainment for readers who are enjoying Roos's ``Pet Lovers' Club'' books and want more of the same. Illustrations not seen. (Fiction. 9-11)