The second in Dario Argento’s “Animal Trilogy” with The Bird with the Crystal Plumage and Four Flies on Grey Velvet, this film isn’t one of the director’s favorites and it failed to follow up on the success of the first film in the United States, although it was very popular in Italy. It’s filled with a lot more humor — it still has plenty of shocking moments — and kind of meanders around. But there’s still so much to enjoy.

Franco “Cookie” Arno (Karl Malden) is a blind man who is obsessed with solving puzzles. One comes to him in real life as he walks at night with his niece Lori. They overhear a man plan to blackmail someone, then that man breaks into the Terzi Institute. We meet our second hero, the reporter Carlo (James Franciscus) when he investigates the affair.

The head of the institute, Dr. Calabresi, looks at his files in his office and phones someone who agrees to meet with him. He tells his fiancee Bianca (Rada Rassimov, the sister of Ivan, which you can tell by her eyes) that whatever was taken could be a big step forward. As the doctor waits on a train platform, he’s pushed off a train platform. This brings the two heroes together and starts a string of murders, as anyone connected to the mystery is quickly killed.

It turns out that the Terzi Institute is able to isolate the chromosomes that point to evil tendencies within people and they have a miracle drug that can change that. Carlo also becomes involved with  Professor Terzi’s daughter Anna and they’re followed by both the police and the killer.

From milk being poisoned to dead bodies being searched in the middle of the night inside a crypt, the noose tightens around our heroes’ necks, with even Cookie’s niece being kidnapped and in danger. And oh yeah — his girlfriend and her adoptive father have had an incestuous relationship for years.

There’s a rooftop battle that may or may not take out one of the protagonists — the movie doesn’t even tell us — and finally the killer is knocked down an elevator shaft, his hands bleeding as he tries to grab the cable to stop him. It’s one of the few moments of sheer awesome in this film, but hints that greatness is in the future of Argento’s films.

You can watch this movie for free on Vudu and on Amazon Prime.