A serial killer named The Shark is terrorizing London by killing his victims with a speargun and then, dressed in a scruba-diver's wetsuit, using the city's sewer tunnels to make his getaway.
| Actor | Role |
|---|---|
 Joachim FuchsbergerInspektor Ward | Inspektor Ward |
 Brigitte GrothumLeila Smith | Leila Smith |
 Elisabeth FlickenschildtNelly Oaks | Nelly Oaks |
 Klaus KinskiGregor Gubanow | Gregor Gubanow |
 Eddi ArentBarnaby | Barnaby |
 Richard MünchDr. Collins | Dr. Collins |
 Jan HendriksRoger Lane | Roger Lane |
 Heinz EngelmannMr. Broen | Mr. Broen |
 Siegfried SchürenbergSir John | Sir John |
 Hela GruelAnna Smith | Anna Smith |
 Hans PaetschRechtsanwalt | Rechtsanwalt |
 Rudolf FennerBig Willy | Big Willy |
| MManfred GreveSergeant Frank | Sergeant Frank |
| GGertrud PreyNurse | Nurse |
 Friedrich G. BeckhausBetrunkener | Betrunkener |
| FFrank StraassDonovan | Donovan |
| WWerner Van DeegNachtwächter | Nachtwächter |
| JJoachim WolffPolizist | Polizist |
 Alfred VohrerEdgar Wallace ( Voice ) | Edgar Wallace ( Voice ) |