Double Crossing (A Nancy Drew and Hardy Boys Super Mystery #1)

AMERICA'S TOP TEEN DETECTIVES TEAM UP WHEN A CRIME WAVE HITS THE HIGH SEAS

NANCY DREW is enjoying a luxury cruise aboard the ship where her friend George is the new social director. It seems like great fun until Nancy overhears a plan to sell CIA secrets to another country. Her vacation turns into a high-risk hunt for a deadly secret agent.

Meanwhile...

THE HARDY BOYS are working undercover on the same cruise ship--Joe in the kitchen, Frank as photographer--trying to track down a dangerous group of thieves who prey on rich passengers.

But when murder comes aboard, Nancy, Joe, and Frank find they're in the same boat--facing death on all sides...