"Do we have everything?" asks Matthew's dad.
"NO!" yelled Matthew.
"No?" said his dad.
"No!" said Matthew. "We don't have dog."
"Dog?" said his dad.
"We don't even OWN a dog!"
"I know," said Matthew. "Now would be a good time to get a dog."
Matthew wants to take his sandbox too, but his dad assures him there will be a sandy beach where they're going. Once they arrive, Matthew meets a girl making a big sandcastle and a big sand dog as part of a contest. Matthew is determined to create something so wonderful, the judges will think it's real.
When he wins, Matthew shares his prize with his new friend and her giant sand dog.