Michael Crichton directed from Robin Cook's great novel. There are huge gaps in logic, but the film is so exciting and entertaining those can be forgiven. It's fairly well-directed and well-done overall. There are many great sequences--Bujold being stalked by a killer in the hospital late at night; a visit to the creepy Jefferson Institute; some lovely views of Cape Cod MA; Bujold, and then Douglas, tracking a suspicious oxygen line and the "accidental" death of a janitor. Also there's Jerry Goldsmith's loud, pounding score moving the picture along and, best of all, this was shot on location in Boston.
The acting is so-so. Douglas and Bujold are OK as the leads. Richard Widmark is having the time of his life playing a hospital administrator. Rip Torn and Elizabeth Ashley also turn in good performances. Also look for Tom Selleck, Ed Harris (with hair!) and Joanna Kerns in bit parts.
A very good movie. However you do have to deal with some very dated dialogue of Bujold trying to make it in a "man's" world. Also be aware that this is pretty extreme for a PG rated movie--there are fairly clear shots of Bujold's body during a shower scene and plenty of nude, dead bodies in a freezer sequence and some really gruesome scenes throughout the hospital.
This film has disappeared for some reason. It caused a lot of excitement around here when it was filmed in 1977 and was a big hit in 1978. Then it just disappeared. That's surprising considering how the careers of Cook, Crichton and Douglas have taken off. It deserves rediscovery.