Abby, a pet-sitter, is dismayed when she is asked to care for her annoying classmate Dirk's ant farm over the weekend, but her little sister Tess helps her see that Dirk and his ants are not so bad.
When Abby and and her little sister Tess are hired to pet-sit a lizard named Angus, Angus disappears and Abby blames Tess until she gets into bigger trouble, and only Tess can save her now.
Abby is thrilled when Mrs. Wilson asks her to look after her two pet goldfish, but when her little sister gets involved, Abby has to think fast to save the day.
Abby and her sister Tess nearly run into trouble when they agree to participate in an animal-assisted activity program at the hospital during which they are assigned to bring a talking parrot to visit Elliot, a boy who has become very depressed since being in a car accident.
After Abby and Tess agree to pet-sit for Ms. Fitzpatrick they are curious as to what kind of pet she has--and hope for a puppy--only to discover that Prissy is actually a pig, but when peculiar things start happening Tess wonders if Prissy has magical powers.
Pet-sitters Abby and her little sister Tess run into trouble with their client and each other when they are hired to care for a lizard while its owner is out of town.
