Jack's furry housemates, Kitty and a mutt named Belle, patrol and guard his house each day after he leaves for work. However, they have different investigative styles, which results in some tension between them. Ever-vigilant Kitty diligently tracks down mice that might be tempted to go after food. Laid-back Belle mostly snoozes and snores, at least until the doorbell rings. At that point, she raises a ruckus, but always heads back to continue her nap. One day, a burglar breaks into the house. To catch him, the animals learn that they really do need one another's help, despite their differences.