Other editions of book Magic Tree House: Books 9 and 10

In Dolphins at Daybreak, it's sink or swim for Jack and Annie when the Magic Tree House whisks them off to the middle of the ocean. Luckily, they find a mini-submarine on a coral reef. Unluckily, they are about to meet a giant octopus and one very hungry shark. Will the dolphins save the day? Or are Jack and Annie doomed to be dinner? In Ghost Town at Sundown, Jack and Annie wonder if the town is haunted when the Magic Tree House carries them to the Wild West. But before they can say "Boo!", they rush headlong into an adventure filled with horse thieves, a lost colt, rattlesnakes, and a cowboy named Slim. Will Jack and Annie have time to solve the next Tree House riddle? The answer may depend on a ghost.