Mystery of the River Boat 1944 serial 

#cliffhanger #serial #action
Deposits of "Nitrolene", a high-energy fuel, have been discovered in swampland near Duval's Landing in the bayous of Louisiana by Dr. Hartman, who signs an agreement with developer Herman Einreich. After getting the map locating the deposits, Einreich has Hartman killed by his henchman Cassard and departs for Duval's Landing on the riverboat Morning Glory. The riverboat's captain, Ethan Perrin, is one of the three landowners involved, and attorney Steve Langtry, the son of one of the other two landowners, is investigating Einreich's offer for his father's land, but foreign agent Rudolph Toller and his underlings Bruno Bloch and Louis Schaber are also on the Morning Glory trying to get Einreich's map, aided by one of the riverboat's entertainers, singer Celeste Eltree. "Mystery Man" Clayton and his Cajun associate Batiste are also clearly up to no good, but helping Langtry are Captain Perrin's daughter Jenny, the riverboat's steward Napoleon and entertainer Jug Jenks.