This is an excellent European thriller, with a cast culled from both Scandinavia (Norway, Sweden, Denmark) and England. Max von Sydow as Salem, the inmate in an asylum for the criminally insane, does a fine job as the lead, (supposedly) unjustly accused and sentenced for a crime he--maybe--didn't commit. Liv Ullmann (who's Norwegian, not Swedish as some people may think) is just as good as his sister, married to a doctor played by Per Oscarsson. The two of them, with the help of a greedy lawyer and a conniving sister, managed to have Salem convicted of the murder of an innocent farmhand. And Trevor Howard plays the investigating inspector who is equally strong--and certain there's more to the case than meets the eye.
Now someone is killing off the people who had Salem committed. Who could it be? Salem himself is locked away in the asylum, surely one of the dingiest and most desolate institutions ever shown on film. But the doctor shows some loopy behavioral tics, so there's a real chance it could be him.
The answer to the mystery is fascinating. This is not a horror film, as an earlier, extremely well-known and highly regarded reviewer for this venue has said (see below), but a thriller whose details are developed quite well. However, there are two logic gaps that are somewhat puzzling:
1) Why doesn't the bird make any noise before the climactic scene?
2) What happens to the rope once it's used? Does it magically reappear under the boat again?
Don't worry, I'm not giving anything away. You have to see this film to appreciate these questions. And it's definitely worth seeing.