​​​​​​​Humans have spread throughout the solar system which is ruled by the System government based on Earth. Ananke is a super secret System ship out on a trial run with a crew of three. Althea is the programmer primarily responsible for Ananke's unique computer software. She has a far greater attachment to the computer and Ananke than to her fellow crew mates. On their way to Pluto two intruders board the ship. One escapes and dumps a virus into the programming to frustrate their attempts to trace him. The other, Ivan, is held for questioning about their ties to a rebel terrorist Mallt-y-Nos.