Four years after she was possessed by the demon Pazuzu, 18-year-old Regan MacNeil (Linda Blair) is living a quiet life under the watchful eye of child psychologist Dr Gene Tuskin (Louise Fletcher).
To understand and dissolve Regan’s memories of her earlier possession, Tuskin uses advanced biofeedback techniques to synchronise two people’s hypnotic states, overlapping their trance images.
She becomes convinced that something evil is still lurking within her patient and calls in Father Philip Lamont (Richard Burton), a maverick priest haunted by memories of an exorcism that went tragically wrong many years before in Africa.

Ellen Burstyn refused to reprise her role, leaving the film in an awkward spot: it needed a new guardian for Regan, so Sharon Spencer (Kitty Winn) was brought back as her new parental figure.
This critical and financial disaster takes too long (almost two hours) to make its points, and the acting is mostly subdued and sometimes not that good.
The studio tampered with the film after audiences cracked up at the devilish finale.
Sharon sets herself on fire during the incomprehensible ending sequence in a moment so bizarre it can only provoke laughter – and it’s even funnier when she waits to die for minutes so she can have a dramatic final scene.
The studio deleted the original ending, in which Father Lamont and Regan walk out of the Georgetown house into the sunset while the neighbourhood fails to notice that the house has burst into flames, and added a prologue with Richard Burton’s voice discussing exorcism over some stills from The Exorcist.
Exorcist II: The Heretic is a prime example of a sequel that was crying out not to be made. All the African mumbo jumbo is bewildering, the needless explication ruins the original’s mystery, and Richard Burton is clearly miles away (he was reportedly inebriated throughout the shoot).
The film had an unfortunate knock-on effect for Burton, who subsequently had to take a pay cut for The Wild Geese (1978) when his usual million-dollar fee was slashed to $750,000 after the disaster of Exorcist II.
Regan MacNeil
Linda Blair
Father Philip Lamont
Richard Burton
Dr Gene Tuskin
Louise Fletcher
Father Merrin
Max von Sydow
Sharon Spencer
Kitty Winn
The Cardinal
Paul Henreid
Older Kokumo
James Earl Jones
Edwards
Ned Beatty
Director
John Boorman









