10.The Masked Executioner 11.Undersea Warfare 12.Vengeance Under the Big Tp
4. Operation Murder 5. The Mechanical Bloodhound 6. Undersea Peril
7. High Hazard 8. Death Alley 9. Cave of Doom
Chapter Titles: 1. Daredevils of the Air 2. Death Takes the Wheel 3. The Trap That Failed
The last serial produced by Republic Pictures, which made its reputation with serials.