Thanks to Mike, Eleri and Tenak, the battle to convince the people of Oceanus to evacuate to Earth has finally been won, but the tragic loss of Eleri has repercussions for many. Mike, bereft and lost, returns to Earth, but the Solar System itself is threatened by a resurgence of dark forces which further undermine evacuation at Oceanus.

The 'Home System' government is forced to make decisions which have awful consequences for both star systems. So why is Mike compelled to return to Oceanus, and what is the secret he carries inside his body, which makes him a security threat? Who are the traitorous terrorists who also return to Oceanus aboard the navy starship, 'The Monsoon'?

A shocking new danger has arisen in the Oceanus system itself, which might pose a threat to all humankind. Who or what are the mysterious alien beings or artefacts which have arrived en masse? What are they trying to do to Ra, the 'sun' of Oceanus? And will Mike ever be able to help Admiral Tenak, in his efforts with captain Providius, of the research ship, 'Antarctica', to deal with the alien incursion?

The stakes soar even higher when when an unwelcome, maverick, figure arrives from Earth, as the Oceanus system teeters on the brink of total destruction.