The deafening crack of a Royal Marine's sniper rifle marked the start of business as usual in Afghanistan yesterday. "Merry Christmas" quipped a commando, as a second shot tore through the freezing morning air.
The fighting men of 40 Commando were already on patrol as the clocks struck Christmas in Britain. They left their base at 4.30am - midnight in the UK - to probe the Taliban's lines just a few hundred metres from their camp, and it was only a matter of time before the insurgents attacked.
After two and a half hours of creeping along river beds and clearing homes long abandoned to the fighting, a burst of AK-47 fire erupted unseen from a tumbledown compound close to where another patrol was trying to move.
"It was a flock of birds taking flight that brought me on to him," said Corporal Wilf Rees, "I thought something must have disturbed the birds, so I put my sights on the compound and then I saw the muzzle flash."
The Taliban gunman was aiming at a group of Marines who had taken up supporting positions on a stretch of high ground nearby. Moments later a third Kalashnikov burst rang out and Cpl Rees replied with a fierce volley of shots from his sniper rifle.
His target was a hole in a mud wall, about the size of a football, 1,100m from his lookout on the roof of an abandoned farmhouse. "I don't know for sure if I got him, but he didn't fire again after that," the father of two children said.
Christmas was essentially another working day for the men of Charlie Company, at their Forward Operating Base in Kajaki, in northern Helmand. But as they neared the final mile of their patrol, almost five hours after they set out, every man who had one swapped his helmet for a Santa hat. Armed with heavy machine guns, mortars and grenade launchers, the men continued their tactical patrol through a derelict bazaar, grinning like children, but looking like a violent Father Christmas audition.
"It's like groundhog day out here sometimes," said Cpl Richard Thomas, 27, from Aberdeen. "You do the same thing every day and you get the same food. It's easy to lose track of time so it's important to remind yourself it's Christmas."
Their camp is the most isolated British outpost in Helmand. It is too dangerous for convoys to reach the base by road. All of their food, fuel, ammunition and post has to come in by helicopter. Post takes priority over fresh food because there just aren't enough flights to go round.
"I can't remember the last time we got fresh food," said chef James Hampson. "We haven't really got anything festive. Christmas dinner is rations. No turkey. It's chicken stew, spaghetti bolognese and noodles."
Cooks at Camp Bastion, the main British base in Afghanistan, served up more than a ton of turkey breasts yesterday, complete with cranberry sauce, crackers and After Eight mints.
The only culinary nod to Christmas at Kajaki was a precious slice of Christmas cake courtesy of the thousands and thousands of welfare packages sent to Afghanistan this year after Royal Mail agreed to waive the cost of post to soldiers on the front line.
"We got about 50 individual Christmas cakes," said Cpl Hampson, 36, from Warrington. "But we've managed to slice them up, and there should be one for everyone.
"We've got one cracker as well, but that's for the cooks."
The food didn't stop the Marines from celebrating. Their galley was decked out with a flashing Christmas tree and bunting made from red and white tape, usually used to cordon off landmines. In the absence of alcohol, men drank coffee from mugs made out of old mortar tubes.
And the surfeit of post meant everyone had something to open. The commanding officer was sent a toy gun by his children. His deputy was spotted firing pebbles at an old ammunition tin with a catapult that his parents sent him. Other presents included juggling balls, computer games, Subbuteo and Santa suits.
"I normally dress up as Father Christmas for my kids on Christmas morning," said Sergeant Daz Joyce, a father of four children. "So they sent me an inflatable one out, because it's light for the post."
Marine Craig Tucker, a 21-year-old from Weston-super-Mare, Somerset, dressed up as an elf. On top of his green, military issue thermal underwear he wore sand bags for shoes and a green felt hat that his family had posted out to him.
And instead of playing board games such as Risk, watching DVDs, or simply kipping last night, the Marines came together for a festive "pub" quiz.
They all do their bit to keep morale high because they know, as far as the fighting goes, tomorrow and the next day will only bring more of the same. And maybe, if they're lucky, some fresh food.