There are two things George Romero loved bringing to theater screens: zombies and socially conscious horror films. Usually both at the same time. With Monkey Shines he delivered a twisted little story about the evils of animal testing. It follows a quadriplegic man as he forms an unhealthy bond with a lab-animal-turned-service-monkey named "Ella." Things start off cute enough. The adorable Capuchin at first proves to be a charming, shockingly intelligent helper for the disabled protagonist, and the master/pet affection that grows as a result is genuinely sweet leading to quite a few moments that will surely make you go "aww 😊." However, it's not long until you begin noticing that the two are having a very negative effect on each other's behavior and the chimp crap hits the fan. This seems like something that shouldn't work at all as the concept doesn't sound even the slightest bit frightening, but Romero is able to make a surprising amount of tension come from this game of cat-and-mouse with a homicidal primate. On top of making the leading man largely immobile and therefore very vulnerable, he also gives the house where most of the action takes place an atmosphere not unlike that of one in a traditional haunting flick when the situation really begins getting dangerous. Your suspension of disbelief will receive a strong test though when the psychic connection between the man and the beast is introduced. This is only a problem because it's never explained how that's possible. Especially since another character has to inject himself with the same compound being used on Ella in order to experience similar results to his friend who was able to attain them through mere proximity. It never manages to bridge that gap between the scientific and the supernatural. By the time the credits roll as far as we know maybe this monkey just "shines" in the same way as Danny Torrance. That flaw aside however, you'll find no monkey business here. This is a very effective bit of simian terror. Something that is in no small part due to it doing its own unique thing to the point where it still feels original and inimitable to this day. I mean, it's animal rights horror for crying out loud. How many times have you seen that before?