The Head Season 1 Episode 13 - The Invasion Episode Title:The Invasion.Episode Description:Dr. Elliott finds that the tables have turned – he's now the captive strapped to a table. Jim and his friends try to develop the anti-invasion machine without the orb, and soon find that they're running out of time as the Earth is bombarded with Gorks. At the last minute, they get the machine working and thwart the attempts of the parasitic race to take over the world.