He joins Prindle and Quinn in their search of a lost Inca city which they believe holds great treasure. Just when they are about to get on their way, an orphaned pick pocket named Paco steals his wallet containing some important film that would help them find the lost city. They begin a man hunt for the boy but fail to get to him after Herbie helps him escape and get aboard a cruise ship to Panama. While Quinn and Prindle went after Paco while he waited with the plane.
After faling to catch Paco, they regroup and continued their search for the boy and the car by plane. They managed to find them and trick Paco into picking up a passanger. They capture him and fly off leaving behind Herbie to go for help.
Prindle, Shepard, and Quinn find the Inca ruins and to their delight an antique gold disc. They lose it when Herbie captures it and drives away into the dark jungle. They succeed in getting it back and try to escape in their plane but due to the extra weight they have problems taking off giving Herbie and Paco a fighting chance. Shepard struggled trying to get the plane airborne and in process it loses its wings, tails, and main propeller
In the end Shepard and his partners are arrested by the police and lose their gold.