A group of friends, spending the weekend in a house in the isolated countryside, are attacked by a swarm of killer horseflies that feed on human flesh like piranhas. The group soon discovers that the only deterrent that can keep the insects away is THC, the main ingredient that makes up cannabis. Their only hope of survival is therefore given by the consumption of grass, with all the consequences that entails.

When friends who are vacationing in an isolated cabin are attacked by a swarm of deadly insects, they must find a way to destroy the creatures if they are to make it out alive.

Four employees of Island Fisheries come to a sun-scorched, isolated island to negotiate fishing rights with the sullen, paranoid islanders who have good reason to be afraid. Soon after the arrival of the four, a mysterious force the islanders thought was chained forever in the dark basement of the foreboding old Counting House is once again on the loose, savagely killing its women. Caught in a power struggle between rival island factions over how to stop the killing, the mainlanders are jailed. They manage to break out, but with a vigilante mob on their heels, can they reach the boat in time? They do, only to confront the mysterious, terrifying force.

A group of friends is fighting against killer horseflies both in modern and ancient times.