Jack Williams' life is turned on its ear when he is selected by benevolent aliens to be the commander of a ship to defend the Earth against a predator species called the 'Gahkee'. With his adopted brother Tree Allen, his wife Jenny and the ship's hologram interface they call Lon, they prepare for the arrival of the Gahkee. During their training they discover that life seems to be everywhere, they explore the unimaginable world of Jupiter's interior. And they uncover the mystery of Jupiter's icy moon, Europa.

After Maia Kazmi, a fellow astrophysicist of Tree's, joins the crew, Jack discovers that their exploits had not gone un-noticed. Unknown to Jack an obsessed psychopath, General Baston, has other plans for the ship. After an incident involving the crew while hiding out in the Himalayas, Jack decides to reveal the ship to the government. A trusted friend of Jack's late father, retired General Tannon, puts Jack in contact with the most likely military representative, Space Command Director, General Baston. The meeting ends in tragedy for one of the ships crewman and the destruction of the ship leaving.

Synopsis provided by the author.