Mike and Kate must solve a mystery during a World Series between the Cubs and the Red Sox when someone starts ruining equipment, getting players in trouble, and even stirring up an old baseball curse.

"After taking down a mole within their organization, the City Spies are ready for their next mission--once again using their unique skills and ability to infiltrate places adults can't. The sinister Umbra has their sights set on recruiting a North Korean nuclear physicist by any means necessary, and the City Spies plan to keep an eye on his son by sending Paris to the chess prodigy's tournaments in Moscow and Beijing. Meanwhile, Sydney's embedded...