In 1936, Juan Soto paid a boiler works employer named Al good money to turn his back while he stole the Arnhem Ring from the National Museum. He learned that archaeolgists Indiana Jones, Marcus Brody and their assistant Marion Ravenwood had learned of his theft and were coming after him.
He had his wolves capture Jones and his friends after they blew up his crop duster plane but refused to reveal who had paid him to steal the Arnhem ring. Soto then made his escape to a boat when Brody inadvertenly blew up his ammunitions. Jones went after him and fought with Soto until his opponent fell into the water, where he was eaten by sharks