An alien starship crashes in a swamp in a U.S. National Park. Some mosquitos begin to feed from the alien's corpses, causing them to grow to the size of a vulture. These mutant insects became very agressive, killing every human being they find. Will the few survivors fight successfully against this nightmare...?

After the death of his brother, Mick travels to America to seek Justice. Wrongly convicted of extortion and attempted murder, Mick is sent to Pleasant Hill Penitentiary's notorious death block 13. Seething with revenge after discovering the truth behind his brother's death, Mick's rage ignites an explosive riot as he makes a daring escape from Death Block 13.