Okay, I was right about the cheesy effects and sketchy plot, but the rest? Not so much.
This is one of those films in that uncomfortable middle ground in the B-movie hierarchy – it's not sensational enough to be a guilty pleasure or awful enough to be unintentional comedy, yet it's far too incompetent to be considered good on its own merits.
The basic premise is that extraterrestrials are lurking around an unspecified location in the UK for reasons that are never entirely made clear. These aliens can make themselves invisible, but they apparently show up in photographs, as a photographer inadvertently takes pictures of them during a photo shoot with a beautiful female model in the woods. (Note to Italian exploitation fans: She remains fully clothed.) The photographer takes the photos to a journalist and complications ensue; the aliens pursue and abduct the photographer, killing a bystander in the process. The police and the military get involved. More people die. (Note to Italian exploitation fans: There is zero gore.) The journalist consults with a paranoid UFO researcher, and both of them wind up being pursued by shadowy government agents known as the Silencers, along with the aliens. It's basically like an extended episode of the X-Files.
The plot is full of holes and is nearly incoherent at times, which is not necessarily unusual for 70s Italian fare, but the filmmakers take far too long getting to the point. The screenplay and direction are limp and leaden for roughly the first hour of running time; there is virtually no sizzle or excitement until the third act, by which time the viewer is hardly paying attention. Like the American UFO researchers who apparently inspired this piece, the filmmakers evidently took themselves far too seriously to have any fun.
It would be neglectful of me not to explain the title of my review, and give some examples of the filmmaker's incompetence while I'm at it:
~ The sequences of the "invisible" aliens stalking the characters are filmed in the first person, using a fisheye lens, accompanied by a mindless droning high-pitched "chirp-chirp-chirp-chirp" synthesizer track and an occasional metallic heavy-breathing sound. As the aliens approach, the room lights go out, and the characters usually stand still rather than investigating why the lights went out as most normal people presumably would. (Note to Italian exploitation fans: Although the beautiful model is involved in these sequences, she remains fully clothed here too, and the aliens never do anything truly exciting like, say, beheading a character.) The director obviously intended for these sequences to be suspenseful, but he relies on them too much and drags them out far too long – one gets the sense that he was simply padding the movie's running time. What's worse, I could still hear the obnoxious "chirp-chirp-chirp-chirp" in my head the morning after watching the film.
~ The film's British locale is never believable. Not only do none of the buildings look British, but the cars are left-hand drive, and characters' offices and apartments are decorated with picturesque posters with British tourist attractions on them, making the sets look as if they were decorated by a travel agent – which they probably were.
~ Important and potentially exciting plot points happen off-screen. Several deaths are either only discussed, or we only see the aftermath as the police are investigating. What's worse, most of the deaths that occur on-camera are dull – the aliens kill with mysterious "radiation poisoning" and the characters merely keel over. We also never actually see the aliens abduct a character; the abductions are merely implied by fast edits of flashing lights, the camera zooming in on the open door of the flying saucer, and the character appearing inside.
~ The dubbing is truly awful, and annoyingly vacillates between spelling out the letters "U-F-O" and pronouncing it like an acronym, "You-foe." The movie also features some of the most atrociously overblown, pretentious, and utterly nonsensical dialogue I've heard since watching 'R.O.T.O.R.' On the other hand, hearing Martin Balsam being voiced by another person who sounds nothing like him is rather novel and entertaining. (Mr. Balsam must have been really hard up for a paycheck at this point in his career.)
~ The Silencers are some of the sloppiest secret agents in movie history; they travel in an enormous and conspicuous black Cadillac, frequently tailing other characters by only a few car lengths, and they hand off a "secret" audio tape in the middle of a city street in plain view of the character whose conversation they just recorded. In another sequence, the head Silencer dramatically puts on sunglasses indoors before shaking down a character, presumably to conceal his identity, but then he takes them off!
~ When the journalist character finally goes Action Hero in the final act, it comes across as unbelievable, but at least this results in a beat-down sequence that's arguably the film's only high point for Italian exploitation fans (I won't spoil it for you).
~ The ending is rather sudden, and was probably intended to be ironic and cynical, but it came across to me as lazy on the part of the screenwriter and director.
Frankly, if you're looking for low-brow sci-fi thrills, I would skip this one.