Cloud on Silver — John Christopher

A disparate group of Londoners are brought together by Sweeney, a mysteriously charismatic man of wealth, for a luxury cruise in the South Pacific â€" they know not why. Sailing far from the normal shipping routes, the ship weighs anchor just off an uninhabited tropical island. Whilst its passengers are ashore exploring, the ship catches fire and sinks beneath the waves. With no means of communication with the outside world and no hope of rescue, passengers and crew must find a way to survive. In the scramble for power that ensues, the distinction between master and servant becomes meaningless as the more ruthless among them clamber to the top. The inscrutable Sweeney, meanwhile, sits alone on a hillside. Coolly aloof, he watches the veneer of civilization disintegrate as his fellows fall prey to fear, desperation, barbarity … As for Silver Island itself, with its lush vegetation and exotic fruits, it had seemed like paradise. But as the days pass, a subtle sense of unease gains momentum, and the realisation gradually dawns that all is far from well in this tropical Eden.