Summer vacation starts on a positive note as Tom and J.D. come up with a plan to mate J.D.'s dog, Brownie, with Lady, a dog owned by Frank and Allan Jensen, two brothers the same ages as Sweyn and Tom.
Meanwhile, Sweyn and Tom teach J.D. to swim by throwing him in the ol' swimmin' hole. Like you do.
This idyllic summer goes south fast, though, when Frank, Allan, and Lady get lost in Skeleton Cave. It's named Skeleton Cave for the skeletons found there, so things don't look good for the Jensen brothers and their dog.
Like the rest of the townsfolk, Tom is concerned. Unlike the rest of the townsfolk, he's afraid he'll lose money if the boys aren't found, but he won't say why.
For two days, Uncle Mark leads the search, using seven thousand feet of rope.
When the grown-ups are ready to give up, Tom puts his great brain to work and figures out how to find Frank, Allan, and Lady.
Essentially, the plan consists of letting Brownie follow Lady's scent. Lady is in heat, so Brownie is extra-motivated.
Tom and Uncle Mark take Brownie into the cave alone, and it's a tense few hours.
Finally Tom emerges victorious, with everyone safe and sound, if a little worse for wear.
The crowds cheer him all the way home and even stands in the street until he makes a victory speech.
Feeling extremely jealous over all the attention Tom is getting, especially since Brownie is his dog, J.D. asks about that fortune Tom is protecting and is told to mind his own beeswax.