When students and teachers at Kings Park School start acting strangely, Tom and Benny fear their enemies have returned and soon suspect alien activity centred on the mysterious Room 12.

When Varg returns with a new wife, the Lady Lyzera, Tom, Benny and Ursula race against time to defeat the evil Prospector and escape the clutches of the Nekross.

Tom is suspicious when Benny gets an invitation to help an eccentric scientist at the Brook Mill radio telescope.