Years after fleeing his ancestral home with his mother, Jason returns home to claim his birthright, only to find his way blocked by his evil cousin Thomas. In order to reclaim his title, Jason must do battle with his cousin, who calls upon the members of the deadly Hellfire Club to stop him.
| Actor | Role |
|---|---|
 Keith MichellJason Caldwell | Jason Caldwell |
 Adrienne CorriLady Isabel | Lady Isabel |
 Peter CushingMr. Merryweather | Mr. Merryweather |
 Peter ArneThomas - Earl of Netherden | Thomas - Earl of Netherden |
 Kai FischerYvonne | Yvonne |
 David LodgeTimothy | Timothy |
 Bill OwenMartin | Martin |
| MMiles MallesonJudge | Judge |
 Martin StephensJason Junior | Jason Junior |
 Andrew FauldsLord Netherden | Lord Netherden |
 Jean LodgeLady Netherden | Lady Netherden |
 Skip MartinJoey | Joey |
 Francis MatthewsSir Hugh Manning | Sir Hugh Manning |
 Desmond Walter-EllisLord Chorley | Lord Chorley |
 Denis ShawSir Richard Benlow | Sir Richard Benlow |
 Peter HowellWilliam Pitt - Earl of Chatham | William Pitt - Earl of Chatham |
| RRupert OsborneThomas Junior | Thomas Junior |
 Caron GardnerSpecialty Girl (uncredited) | Specialty Girl (uncredited) |
 Cornelia FrancesYoung Woman (uncredited) | Young Woman (uncredited) |
| TTony ThawntonCaptain (uncredited) | Captain (uncredited) |
| FFredric AbbottPrison Guard (uncredited) | Prison Guard (uncredited) |