Struggling writer Myles Clarkson (Alda) meets talented but dying pianist Duncan Ely (the creepy Jürgens) who bestows upon the former the sweet gift of success, wealth and prestige.

But how, and at what price fame?

Turns out Ely and malevolent daughter Parkins head up a devil worshipping coven adept at body switching and life swapping.

Will Myles succumb? And will his lovely wife Paula (the flawless Bisset) survive with her soul intact?

Echoes here of Roman Polanski's Rosemary's Baby flatter this well made occult piece supported by elegant set designs, good performances from Alda and Bisset, and a moody ambience throughout.

The weighty, downbeat 'win at any cost' ending is a nice plus.

With an excellent dissonant-flavored score by Jerry Goldsmith.

Director Wendkos also did a number of notable thrillers and horrors for television, including Fear No Evil (1969) and Terror on the Beach (1973).