Yu Ominae is a Spriggan, a member of an elite corps of biologically engineered warriors created by the secret organization ARCAM, who finds himself involved in a baroque adventure centred on the newly discovered Ark of Noah. The Ark is actually an extraterrestrial vehicle with the power to alter the Earth's climate and spawn new animal species. A sinister cadre of rogue Pentagon generals want it and they dispatch a corps of murderous cyborgs lead by Colonel MacDougall, a monstrous child who is also the product of biological experiments, to capture it. ARCAM is determined to prevent the generals from gaining control of the Ark's awesome powers. Yu battles his way to victory through car chases, sword fights, shootouts, explosions, knifings, and psychic blasts, with a little help from fellow Spriggan Jean-Jacques Mondo.