In Harlington there is one of the oldest and most successful film studios. The film studio would thus be used as an excellent cover for any vehicles which might be spotted by those not privvy to the real work being done there. This is the head of the whole defense system. A nuclear submarine, Skydiver prowls the ocean depths, ready to strike at any intruder able to bypass the outer defences. When an incoming UFO is detected in earth atmosphere, Skydiver can launch SKY 1, a fighter aircraft able to take off from sea depths and to attack and destroy almost any grounding alien spacecraft.
Mobiles generally operate in group of three.
Led by the charismatic Roj Blake, a band of renegades are able to convince the computer Zen to allow them access to the Liberator , a vastly superior alien spacecraft. They set out to seek revenge and overthrow the evil empire of the Earth Forces Federation. Later Blake is presumed dead, and Avon, his cold hearted demeanor unimproved, takes over leadership of the renegades and the Liberator . Rather than a popular leader, Avon holds the reins only because no one else can seem to muster his level of knowlege or confidence. Also Avon escalates his verbal assault on Villa, the cowardly thief becoming the whipping boy in almost every episode following Avon's ascension to the leadership role.