Ballpark mysteries. Main series

While visiting New York's Yankee Stadium with Kate's mother, cousins Mike and Kate decide to investigate the rumor that the ghost of Babe Ruth is haunting the stadium.

"Before an Astros game, Mike and Kate take a tour of the Houston Space Center and meet Commander Nicholas Rice, an astronaut. He'll be signing autographs and showing a very rare moon rock at the game later. But when it's time for Commander Rice to throw out the first pitch, he never turns up. Someone knocked him out, tied him up, and stole the moon rock! Can Mike and Kate figure out who the Astro Outlaw is?"--Page 4 of cover.

Next up to the plate—book #6 in our early chapter book mystery series, where each book is set in a different American ballpark! 
Ivy-covered walls—they're the most famous part of the Chicago Cubs' historic ballpark, Wrigley Field. Mike and Kate can't wait to get down on the field to see the ivy for themselves. But when they do, they're horrified to discover patches of the ivy have been ripped away! Who would want to sabotage the...

"Mike and Kate are visiting the Miami Marlins ballpark when some rare animals from the ballpark's fish tanks go missing"--

Through the window of their hotel room in the Toronto Blue Jays baseball stadium, cousins Mike and Kate spot strange blue lights flashing across the bullpen and decide to investigate.

Cousins Mike and Kate set out to catch the person who is selling counterfeit baseball shirts in the Texas Rangers' ballpark.