Torus

22,000 miles high, a satellite somersaults out of control
For Harry Dysan, maverick director of the National Security Agency, the news is very bad indeed. The satellite flaunts a hole punched by a weapon that makes all others obsolete. With devastating precision, the torus beam can focus and project the energy of an atom bomb into outer space.
Determined to unlock the secrets of the ultimate space Weapon, Dysan finds the one person who can trace its source. But Lesa Wessex, a brilliant data scanner and refugee from Vietnam, has her own reasons for helping him. And as their joint hunt for the torus leads them to a remote island in the Pacific, it becomes clear that the satellite was merely target practice... 
James Follett is the bestselling author of Mirage, A Cage of Eagles, Ice, Swift and Dominator, also available from Mandarin.