Chapter titles:
1. The Mechanical Terror.
2. The Edge of Doom.
3. Flames of Fate.
4. The Fatal Search.
5. Rocks of Doom.
6. A Friend in Disguise.
7. A Scream in the Night.
8. Death in the Dark.
9. The Secret Tunnel.
10. Forty Thousand Volts.
11. The Mad Professor.
12. Shadows of Destiny.
13. The Gorilla at Large.
14. His Last Flight.
15. Justice Triumphs.
This was Columbia's 26th serial.
In chapter 5 Nordick leaves a bucket of water for Thor to drink. When Nordick returns a few minutes later after his phone call with Ernst, the bucket is gone from Thor's cage.
The character Flash consistently calls the robot "Mr. Rabbit".