Eddie brought his baseball cards to school and now they are missing. It's time for Jigsaw Jones to step up to the plate and solve this mystery.

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.

Joey, who loves baseball but is not very good at it, finds a valuable 1909 Honus Wagner card and travels back in time to meet Honus.

In hopes of winning the valuable baseball card that he and his new friends have hidden in a remote cave outside Granite Falls, Washington, Andrew asks the gruff P.E. teacher at his middle school to help him become a long-jumper.

When Pine City Porcupines' bat boy Chad breaks an important unofficial rule of baseball: Do not talk to the starting pitcher when he has a perfect game going, the team may lose the game unless Chad can find a baseball card to help break the superstition.

Joe Stoshack travels back to 1919, where he meets Shoeless Joe Jackson and tries to prevent the fixing of the World Series in which Jackson was wrongly implicated.

When Joe Stoshack's dad ends up in the hospital after a car accident , he has tow words he has to say to his son,: Mickey Mantle. For Stosh has a special power with a baseball card in hand, he can travel back in time. And his dad has a rare card - Mantle's valuable 1951 rookie card. "I've been thinking about it for a long time. Go back to 1951. You;'re the only one who can do it," Dad whispers. That night Stosh grips the card and prepares for another...

With his ability to travel through time using baseball cards and photographs, thirteen-year-old Joe and his mother go back to 1863 to ask Abner Doubleday whether he invented baseball, but instead find themselves in the middle of the Battle of Gettysburg.