Where's Sunday?

Sally's much-loved puppy, Sunday, is young and bouncy and still needs some training: that's Sally's job, because Sunday is her puppy. There are still a few things Sunday hasn't learned, like coming when she's called. Late one day, when Sally's family is driving home from the beach, her little brother feels sick and Dad has to stop the car at the side of the road. In those few moments Sunday escapes. Nobody realises she's gone until some time later. Dad turns the car around and drives back to the place where they stopped, but they can't see Sunday anywhere. Will anybody find her? Sally can't sleep for worrying. And then the phone rings ...