After unscrupulous collector S. Wendell Palamino cons him out of a valuable baseball card, sixth-grader Griffin Bing puts together a band of misfits to break into Palomino's heavily guarded store and steal the card back, planning to use the money to finance his father's failing invention, the SmartPick fruit picker.

When Joe travels back in time to 1944, he meets the Milwaukee Chicks, one of the only all-female professional baseball teams in the history of the game.

To keep Teddy "Bear" Larrabee happy and slugging, Chad the bat boy has to figure out what a crabby fan would be willing to trade for Teddy's lucky homerun ball.

Roger's friend Kenneth uses an unusual sea vehicle of his own design to take them to an underwater cave, where a cache of old loot gathered by the mermaids turns out to contain a lot of very valuable old baseball cards.

With his ability to travel through time by using baseball cards, Joe goes back to 1947 to meet Jackie Robinson, turning into a black boy in the process.

Nine-year-old Artie Jensen gets help from his new pet Ghost Dog, an invisible pug, after someone steals the valuable baseball card his grandfather gave him.

"Joe 'Stosh' Stoshack uses his power to time travel using baseball cards to go back to 1951, when Bobby Thomson hit the famous Shot Heard Round the World home run to win the National League pennant for the New York Giants"--

Brian and Paul venture back in time to try to rescue a collectible baseball card on the Titanic before the ship sinks.

Biff, a friend of Frank and Joe, buys a rare card only to find it's a fake. Frank and Joe discover that the baseball card scam is only a small piece of a larger criminal operation.