Sergeant Joe Sasser, tucked into the reverse slope, set up his radio:

"Ready, Lieutenant." Weiss called Sergeant John Corn to move up beside him before scrambling up the precipice to the top. The sun glared. Head low, body flattened, elbows stretched far apart and resting on the ground, binoculars up to his face, Weiss searched and waited.

The Germans began firing-88s and mortars. "Smoke from the muzzles of the German guns wreathed their position like smoke rings from a cigar," Weiss remembered. He called out to Sergeant Corn, "Fire Mission. Enemy battery," and gave the coordinates. Corn passed it on down to Sasser, who radioed in the coordinates.

Weiss could only wait in apprehension. Sasser called up softly, "On the way."

"A freight train roared by from the left side," Weiss said. "Almost instantly clouds of smoke broke near the German position. I shouted an adjusting command to Corn who passed it quickly to Sasser and on to battalion. The next salvos were right on target." That German battery was out of action.

Shells came in from the left from six enemy self-propelled guns. Weiss repeated the sequence with similar satisfactory results. Then a single tank and yet another battery fired on Hill 317. Weiss called in a barrage on the tank that set it ablaze, then turned his attention to the battery. The follow-up rounds were on target. "The enemy," Weiss noted with satisfaction, "had been neutralized."

Weiss called for some thirty fire missions that day, scrambling up the ridge each time the Germans began firing. Some half-dozen other observers were doing similar work that day.

EVEN AS THE Mortain offensive began, Patton's forces had overrun Le Mans and turned northwest, towards Argentan. Montgomery and Bradley agreed that the Americans should halt outside Argentan to await the Canadians (with the Polish 1st Armoured Division in the lead) coming down from Falaise. When they met, the entire German army in Normandy would be encircled.

The men of the 2nd Battalion of the 30th Division were on their own. By not reinforcing Hill 317, Bradley tempted the Germans to keep on pushing west. But how long could the men on the hill hold out? For five days the hill was surrounded. While the Americans and Canadians were closing the envelopment behind them, the Germans continued the offensive. They threw tank columns into the attack: American artillery, responding to Lieutenant Weiss and the other observers, broke them up.

On August 9, German light tanks tried again. There were five attacks in the first hour that morning. Weiss, who had not eaten or slept for 48 hours, was operating on adrenaline. He was 21 years old and filled with the wonderful feeling that he was making a difference in a crucial battle. The frantic activity-shooting up tanks, troops, guns, and vehicles-cut through his fatigue and masked it. He was exhilarated. On the third day, still without rest, he sent this message: "As sleepy, tired and hungry as I am, I never felt so good as I feel right now."

The observers were calling up to P-47s and British Typhoons whenever they saw German tanks on the road. Meanwhile, elements of the 4th, 9th, and 35th divisions hammered the German flanks. As on Hill 317, forward observers on high ground called in fire missions. Eighteen-year-old Private Robert Baldridge was in the 34th Field Artillery Battalion, 9th Division. He recalled, "The visibility from the top of this hill was excellent. What a change it was from the narrow confines of the hedgerows. We saw some twenty miles distant, even the spires of Mont-St. Michel."

That day the leading elements of the American forces got into Alengon. Argentan was but 40 kilometres to the northwest. But the GIs were meeting stouter resistance because the Germans were awakening to their danger. Major Charles Cawthorn, an infantry battalion CO in Patton's army, recalled that this was not "a game of Allied hounds coursing the German hare," as the press was reporting it, but rather the hunt after "a wounded tiger into the bush; the tiger turning now and again to slash at its tormentors, each slash drawing blood." Kluge, meanwhile, was pleading with Hitler to allow him to retreat to the east while the gap was still open.

ON HILL 317 the position was precarious-no food, ammunition running low, and worst of all, the radio batteries were dying. Sergeant Sasser retrieved discarded batteries and set them out on rocks. The sun restored some life. He switched batteries several times a day, restoring one set while using another. Even so, by the end of the fourth day, it was doubtful that he could keep them going.

The GIs had long since cleaned out the chicken coops and rabbit pens around the half-dozen farms on the hill, along with the fruit and vegetable cellars, and were eating raw vegetables gathered from the gardens-when they got anything to eat. Medical supplies had long since run out. After the fourth day Weiss reported, "We could see no end." Incoming radio messages told the 2nd Battalion to hold on, help was coming. But when?

Lieutenant Ralph Kerley commanded E Company of the 2nd. After four days and nights of fighting, he was exhausted, discombobulated, but he kept at his work. At midmorning of the fifth day, studying the panorama below him through binoculars, he spotted a German mortar crew served by a half-dozen men.

"Sergeant," he called out to the leader of his own mortar team, "how many rounds do you have left?" "One, sir."

Kerley paused, thought about what relief it would bring if he could put that mortar out of action, thought about the danger he would be in if he was out of shells. "Do you think you can hit the son of a bitch?"

"Yes, sir. I reckon I can."

"Then blow his ass off."

The sergeant gathered up his crew and brought the 60-mm mortar assembly forward. Kerley watched the enemy mortar crew loafing, lying around, sunbathing, laughing. Occasionally one man would stroll back into the bushes and emerge with a shell, drop it down the tube, and shortly thereafter the shell would explode to the right or left, showering Kerley with rocks and dirt.

Kerley studied his map, turned to the sergeant, pointed, and said, "Put it right here."

The sergeant made his own survey with his binoculars. A private, his M-l slung across his back, clutched the sole remaining mortar shell for dear life against his belly. Kerley and the sergeant talked quietly about wind, distance, elevation, made adjustments on the elevating screw. One last consultation, one minor adjustment.

Satisfied, the sergeant turned to the rifleman with the mortar shell. The private stretched his hands out to the sergeant as if passing off a newborn baby. The sergeant took the shell, kissed it, dropped it in, ducked, and called out, "On the way." Kerley steadied his glasses, peering intently, holding his breath.

Klaboom! The shell exploded less than ten metres from the enemy mortar team. Two of the men leapt up and dashed away. Two others grabbed their mortar and ran. Kerley started breathing again. "Nice work, Sergeant," he called out.

ON AUGUST 11 Kluge finally got Hitler's permission to break off the attack at Mortain and begin the retreat through the Falaise gap. It was a momentous, if inevitable, decision, because once the retreat began, there was no place to stop, turn, and defend short of the Siegfried Line at the German border. The line of the Seine could not be defended: there were too many bends in the river, too many potential crossing places to defend. Once the retreat began, the Battle of France had been won.