''Yes, it was your fault a chunk of cave roof collapsed on you,'' David said. ''What an idiot.''

''Ah'm just holding you up. You have to leave me.''

''What, and miss your cheery Scottish temperament?''

''Go an' fuck yourself, sir.''

''That's the spirit.''

At dawn, as much through luck as skill, David managed to catch and kill a lizard. He chiselled off its head with a sharp stone and they took turns to drink drips of its blood. Then they took turns to vomit.

The sun blazed, Ra at his least forgiving. The paratroopers draped their battledress blouses over their heads and felt their bare backs and shoulders start to blister. The horizon was one long wavering line, melting into the blue of the sky. However far they trudged it never came any closer.

Soon David had almost stopped thinking. All that filled his mind was thirst. His tongue was a lumpen, desiccated object in his mouth; it no longer felt a part of him. His brain throbbed inside his skull like a prisoner beating on the walls of his cell.

McAllister was scarcely walking any more. David and Gibbs were carrying him, and every step they took with his extra weight seemed to drain one more ounce of hydration out of them, one more erg of strength.

Eventually they set him down in the feathery shade of a tamarisk bush. They knew they were not going to pick him up again. Their arms were too stiff to lift him any more, and McAllister was too pain-wracked and feverish to bear any more of being lifted.

A few words hissed from his parched lips.

David leaned close.

''Could murder a brew,'' McAllister said.

''Afraid we're all out,'' said David.

''Whisky?''

''I seem to have mislaid my hip flask.''

Even more quietly, so that Gibbs couldn't hear, McAllister said, ''They bombed us.''