When Ian Carter discovers he has a twin sister, this is just the beginning of an avalanche of discoveries, each more surprising than the last.

An adopted child from birth, Ian learns that his natural parents came from someplace called "Panka," in another galaxy. He had no idea he would someday visit Panka and become a member of its defence force. But first, a bank robbery threatens his sister, Susan, and with the help of their mutual telepathy ability, Ian is able to save her, earning a mortal enemy in the process.

Ian's sister, Susan, a very bright physics major in university, is destined to make her own contribution to Pankan defence against the Skaylink and the Thrax, both of whom have set their sights on conquering Earth.