Happy couple Jason and Alexandra lose their sail yacht in a storm and are grateful to get picked up by Captain Jim Bigelow's commercial carrier. Suspicious about the ship's doctor and realizing the ship is improbably empty and the radio not broken as the crew claims, Jason starts snooping around. Bodies on meat-hooks, genetic experimentation and giant spiders are what he finds.

Investigating the mysterious deaths of a number of farm animals, vet Rack Hansen discovers that his town lies in the path of hordes of migrating tarantulas. Before he can take action, the streets are overrun by killer spiders, trapping a small group of townsfolk in a remote hotel.