LD 50 Lethal Dose is a 2003 horror film directed by Simon De Selva, produced by Alistair MacLean-Clark and Basil Stephens and written by Matthew McGuchan.

A group of animal rights activists set off to free an imprisoned colleague from a terrifying ordeal but their rescue mission turns into a series of twisted and mind bending incidents.

At the remote lab where Gary is being kept, the group discovers the place abandoned, and soon finds themselves locked in a subterranean level full of labyrinthine hallways and experiment chambers.

They also discover that a powerful electrical force is stalking them, and it has full control of the complex.

The force plays havoc with the would-be rescuers, turning their righteous cause into a death trap.