The farming world Akir is threatened by the tyrannical warlord Sador (John Saxon), who rules the sinister Malmori Empire. Sador's huge dreadnaught (nicknamed "Hammerhead") mounts a "Stellar Converter", a weapon that turns planets into small stars. He demands that the peaceful Akira submit to him when he returns in "seven risings of your red giant", or he'll turn his Stellar Converter on their planet. Zed (Jeff Corey), last of the famous Akira Corsairs, is old and nearly blind. He suggests they hire mercenaries to protect their world. Since Akir lacks valuable resources, its people can offer just food and shelter in payment. Unable to go in person, Zed offers his ship for the job if they can find a pilot. The ship is fast and well-armed, but, despite its Artificial intelligence navigation/tactical computer Nell, cannot defeat Sador alone. Shad (Richard Thomas (actor)), a young man who has piloted the ship and is well known to Nell, volunteers for the recruiting mission.