"SURPRISE! HAPPY BIRTHDAY!" Harry and his dinosaurs love birthday parties, so Harry's disappointed when big sister, Sam, says she's going to one - alone. And Harry finds out that it's the dinosaurs' one hundred millionth birthday too! Harry decides to throw a surprise birthday party, will he and the dinosaurs be able to pull it off? Looking for more adventures with Harry and his dinosaurs? Discover: Harry and the Dinosaurs Go To School Harry and the Dinosaurs United