The Phoenix Equation — Franklin W. Dixon

The final reckoning!

The Hardys have come thousands of miles in search of their father's killers and will go to the ends of the earth to complete the job. From Stockholm to Copenhagen to Berlin, the trail is getting hotter by the minute -- and their mission ever more critical. They've uncovered a shocking new piece of evidence: Fenton Hardy may be alive after all!

But the boys are working without a net, with no one to trust: not the beautiful Ilsa Khoo, not Interpol, not even the U.S. government. Someone inside the operation-- has betrayed the investigation, leaving Frank and Joe out in the cold. They'll have to go it alone and infiltrate Phoenix Enterprises no matter the risks. The time has come to face the truth and face the enemy!