#serial #cliffhanger #action
Nazi spies, led by the mysterious "Master Key", kidnap Professor Henderson in order to acquire his "Orotron machine" which is capable of extracting gold from sea water. FBI agent Tom Brant, aided by reporter Janet Lowe and Detective Lt. Jack Ryan, attempt to rescue him and crack the Nazi spy ring.

1. Trapped by Flames
2. Death Turns the Wheel
3. Ticket to Disaster
4. Drawbridge Danger
5. Runaway Car
6. Shot Down
7. Death on the Dial
8. Bullet Serenade
9. On Stage for Murder
10. Fatal Masquerade
11. Crash Curve
12. Lightning Underground
13. The Last Key