Son of Ingagi opens with ringing church bells heralding the wedding of Bob Lindsay (Alfred Grant) and his bride, Eleanor (Daisy Bufford). On the way to their car, they stop for a moment to speak with Mr. Bradshaw (Earl J. Morris), a divorce… More Son of Ingagi opens with ringing church bells heralding the wedding of Bob Lindsay (Alfred Grant) and his bride, Eleanor (Daisy Bufford). On the way to their car, they stop for a moment to speak with Mr. Bradshaw (Earl J. Morris), a divorce lawyer who apologizes for arriving late. As the young couple drives away, Bradshaw is greeted by a police detective, Nelson (Spencer Williams). They are quickly joined by Dr. Helen Jackson (Laura Bowman), who asks Bradshaw to prepare a will for her. While the young couple celebrates at their new home with their friends, Jackson and Bradshaw conclude their business, quibbling briefly over payment. Jackson then walks to the new couple's house, waiting outside, watching through a window. When she arrives, some of the couple's friends (The Toppers) are performing a musical number in their honor. Following a second song, the partygoers hear an explosion and sirens, which leads Bob to conclude correctly that the foundry where he works has been destroyed. While Bob and the others rush to the fire, Eleanor waits at the house, where she is startled by Jackson. During a conversation with the doctor, Eleanor, who was orphaned as a child, learns that her parents were killed in a tornado. She tells Jackson that she knows that the older woman has secretly performed charitable acts. Jackson reveals that she had been in love with Eleanor's father, and gives her a locket that had been his. The doctor returns to her house and finds her conniving brother (Arthur Ray) waiting there. When he tries to blackmail her out of half of the 20,000 dollars in gold she has smuggled from a trip to Africa, she rings a gong, summoning something else she brought back from her travels -- a giant ape-man (Zack Williams). Having lost control of the situation, the brother jumps out a window and flees. The scene next shifts back to Bob and Eleanor's house, where the young couple finds a mysterious note containing a drawing similar to the design of the locket. Meanwhile, back in her secret laboratory, Jackson tends to the ape-man, bandaging his cut finger. She leaves him alone to go to her study, which is a mistake. The ape-man has watched her mixing potions and tries to imitate her, becoming frustrated and destroying some of the equipment. He leaves the lab, finds Jackson, and kills her. Shortly later, Bob and Eleanor arrive, seeking answers to the note. They find the house empty, but notice the obvious signs of struggle and call the police. Nelson confronts Bob with the will, which leaves the deceased's estate to Eleanor, and accuses him of the murder. Some days pass, as shown by newspaper headlines. While Bob is away at the market, Bradshaw arrives and attempts to persuade Eleanor to sell the house. She goes to the kitchen, leaving Bradshaw alone in the study. He begins to look for the gold, but instead finds the gong and strikes it. This summons the ape-man, who strangles him. Bob returns, and Eleanor notices that Bradshaw is missing. Nelson investigates the new murder, commenting that he's searched the house from attic to basement, except that the house doesn't have a basement. Nelson decides to spend the night in the house. Later, the doctor's dishonest brother returns, this time coming in through the window. He scuffles with Bob, who is knocked unconscious as Eleanor's screams wake Nelson. Nelson again begins to search the house, but pauses to fix a sandwich, which the ape-man takes while Nelson is not looking. The brother finds the secret passageway and the hidden gold, but is himself discovered and killed by the ape-man. The wounded ape-man wanders through the house. Eleanor sees the ape-man and faints. The ape-man carries her to the secret lab, which catches on fire. Eleanor's screams lead Nelson and Bob to the secret passageway. Bob locks the ape-man in his cage and abandons him to the fire. Bob and Eleanor escape, but Nelson is apparently killed. Outside the house, Eleanor, Bob, and the police watch the house burn. Surprising everyone, Nelson stumbles out of the bushes, a sack of gold in each hand. He gives the gold to Bob and Eleanor, who say that they'll use it to buy a new home.