The Escape Orbit

Earth Empire's elite corps of officers are being held as prisoners of war on a remote planet of primitive beauty. It's been a foolproof penal colony - until now. A new prisoner, Sector Marshal Warren, has devised a daring plan to ambush an enemy shuttle and escape the planetwide prison. But as E-day approaches, he discovers that the most treacherous threat is from the enemy within. A pack of violent saboteurs prefers the peace and pleasures of the forgotten island in space to freedom. * Tytuł brytyjski: Open Prison