When Thomas's loveable dog McGrowl is hit by a car, Thomas is heartbroken. But just when he thinks McGrowl will be lost to him forever, the mysterious vet Dr. Minderbender steps in to save the day. After a strange operation, McGrowl is alive, but he has been changed forever. McGrowl now has super speed, super hearing, and superpowerful sight, smell, and strength -- and a few super-funny tics. Now Thomas and his bionic dog must take on the evil Dr. Minderbender and foil his sneaky plans. Can this one-of-a-kind canine superhero save the day?