Isle of Sunken Gold is a 1927 American adventure film serial directed by Harry S. Webb. The film was long considered to be lost, however, chapters 4, 5, and 6 and reel 1 of chapter 7 were recently discovered in a European archive and retranslated back into English. A sea captain obtains half of a map directing him to an enormous treasure on a south sea island. The princess who rules the island possesses the other half of the map, and together they fight off the pirates and natives who would prevent their retrieval of the treasure.

Cullen has hired Tom to try and stop the robberies on his railroad. Knowing Cullen's secretary Holt is tipping off the gang, Tom works undercover by posing as a highwayman. To help him bring in the gang he enlists the help of the hobo DeLuxe Harry.

In order to impress tourists with his bravery, their guide disguises a person in a lion's skin, intending to 'tame' the lion before them. But the plans go awry and a real lion enters the ring.