This was important. The US was assumed to be five years ahead in bio-technology. Travis wondered briefly whether they had got them by independent research or industrial espionage. He decided it didn't matter. He lobbed the grenade.

One of the figures looked up just before impact, tried to throw himself flat as he shouted a warning. Travis let rip with his M-16. The Soviet Greens reeled and died. Gobbets of bloody flesh exploded across the clearing. They didn't scream. Not one of them screamed.

"Come on, Carlo," Travis shouted and headed towards the sound of gunfire.

He sprinted from tree to tree then threw himself on his stomach to worm his way round the edge of the clearing. He assumed Carlo was following.

Keep moving, he told himself, don't let the fear in your gut get control.

Bill-boy was pinned down by the bole of a giant tree. Three soviets kept up suppression fire while two snuck forward.

Why are they here? Travis wondered. Protecting the power station? Same reason as us, field tests? Carlo arrived in his patch of cover. In the distance he heard the whoosh and explosion of Chad's rocket launcher, caught sight of the bright muzzle flash of the Russian guns.

He pointed to one of the Russians who were suppressing Bill-boy. Carlo nodded. They opened fire. Two of the Russians died. The other one started to turn, bringing his weapon to bear on the sergeant. He was cut in two by near simultaneous bursts from Carlo and Travis.

One of the two who had been attempting to reach Bill-boy lay still in the clearing. Bill-boy popped up and shot him, then ducked back into cover as bullets from the right of the clearing thudded into the wood around him.

The night was filled by the roar of automatic weapons and the noise of approaching helicopters. Travis looked at Carlo. At some point the Green had slapped a fleshtone bandage on his arm. "Let's get gone," he said.

Bullets whined around him, impact knocked him over. Most had been glancing shots bouncing from his kevlar body armour. Carlo was not quite so lucky.

He lay nearby riddled with bullets.

Travis watched appalled as he began to move. "Get gone, Sarge, I'll cover you." Travis looked at his ruined face and shook his head. Travis heard footsteps and whirled. It was Bill-boy. His eyes held an insane glint.

"Got that last one, Sarge. Good fight."

Travis turned back to Carlo.