"One and two - three rounds each", the order came. From the mortar pits, six rapid, ear-piercing explosions burst forth. Bullets whistled overhead.
The US Marines were engaged in a battle with the Taliban. Over the radios they could hear them excitedly repositioning, checking on their fighters as the mortar bombs began to explode around them. At moments they could be heard singing fighting songs, seemingly oblivious to the pounding thud of Cobra attacks and Huey helicopters overhead.
This was Mian Poshtay, the US Marines' most southerly outpost, in the heart of Taliban territory. It is, in the words of Lieutenant Colonel Christian Cabaniss, commanding officer of the 2nd Battalion, 8th Marines, "the most kinetic [fighting] part of Helmand right now".
Since being dropped into the heart of the lethal green zone, Echo Company - or America's Company as they are known - have fought 52 out of 68 days. "Welcome to Mian Poshtay," smiled 1st Sergeant Philip LaFountain. "Don't be surprised if the bullets start coming in."
2nd Platoon were patrolling just over a kilometre from the camp when an explosion rocked several of them as they tried to search a compound. From two sides the Taliban attacked, moving forward despite heavy machine gun, grenade, rocket and mortar fire from the Marines. At one point the two sides were just 75 meters apart.
"The Taliban kept advancing and their fire was getting more and more accurate from the east while we were still being engaged from the south. The rounds were snapping inches away," explained Corporal James Greenlee, 23, from Texas.
As the sun went down, with one of their men dead and another injured, the Taliban withdrew to fight another day.
For more than three years the British have expended blood and treasure in Helmand, facing an enemy that has increasingly resorted to roadside bombs. Pleas by commanders on the ground for a large increase in troops fell on deaf ears though 700 soldiers sent to cover the elections, bringing the total to 9,000, will remain.
With US President Barack Obama's troop surge, however, 10,000 US Marines have been sent to bolster numbers and take over districts to the west and south such as Garmsir from the British, while the UK force remained in eastern areas such as Sangin and Kajaki.
On 2 July, 4,000 US Marines were airlifted into Garmsir district. The Americans pushed 20 km to the south dropping troops at key junctions along the Helmand river. Echo Company were ordered to take the southernmost point, a crossroads of canals deep into Taliban heart land. British troops had poked the hornet's nest repeatedly in the past few years but never had the manpower to stay.
The US Marines were told to take the ground and hold it. Dropped into this spot of fertile fields sandwiched by arid desert, they were attacked from north and south. For the next four days, the Taliban fought fiercely to maintain a foothold. At times the two sides eyed each over a canal just 100 meters apart, the insurgents dug into irrigation ditches and trenches around an old disused school, their headquarters.
The Marines triumphed but at a cost. Lance Corporal Charles "Seth" Sharp, a 20-year-old from Georgia known for his irrepressible sense of humour and ability to befriend everybody, was shot in the neck and killed.
"It was hard for his friends. There were some tears but at the time anger at ourselves for allowing the enemy to get so close. We didn't let that happen again," explained Lieutenant Ted Hubbard, 25, from New York.
The US Marines eventually overran the insurgents' headquarters and set up base in the pockmarked, Taliban graffiti-covered, derelict buildings - Combat Outpost Sharp.
In the tiny frontier-like market outside they found kilos of opium alongside the fruit and vegetable stalls as well as an armoury of weapons - mortars, machine guns and rocket propelled grenades (RPGs).
Almost every day since has been a battle for the company - a mixture of men who are veterans of the Iraq invasion, the bloody battle for Fallujah, and Afghanistan, as well as youngsters straight out of training.
COP Sharp has been pounded by small arms fire, machine gun bursts and RPGs while forays into locals villages are repeatedly ambushed. The young Marines joke of a "boring" patrol if they come back without being fired on.
Six have been shot and injured, alongside a British soldier working with the Afghan National Army (ANA) who was hit in the neck, while countless more have had close calls - one Marine was shot in the head but the bullet lodged in his helmet, saving him from certain death.
As they survey their new-found area, they tread carefully through corn and cannabis fields - so high they dwarf the heavily laden and armed Marines, enveloping them in a sickly, sweet, humid blanket - aware that every step is a potential explosion. To date they have been hit up to a dozen times, while double that number have been located and detonated.
One roadside bomb claimed the lives of two Marines from weapons company and seriously injured another while a second killed an ANA soldier outside the camp.
A week ago the senior American commander in Afghanistan, General Stanley McChrystal, called for a complete revamp of military strategy, insisting the International Security Assistance Force had been a bull charging at a matador and it was time to focus on winning the approval of the population.
In line with his review, the Marines' job is not just to hold the ground but to build on it, to win over the trust of the population - "armed social work," as Lt Col Cabaniss called it, adding: "Shooting is getting in the way of winning". It is an inordinately complex task in an area which remained barren desert until the sixties when American aid projects built irrigation canals, drawing inhabitants from all points of the compass.
Every tiny hamlet has a different set of elders and allegiances - populated by people who are fiercely independent and suspicious of outsiders. Taliban fighters have long had a "stranglehold", often living intertwined within the community.
"A man may not be a Taliban hard line fighter but the Taliban may be his best tractor mechanic or his wife's nephew. He may harbour him, feed him but it doesn't make him a bad man. It is not that big a deal to them," explained Captain Eric Meador, 37, commanding officer of Echo Company.
A veteran of the Iraq invasion, who lost 18 colleagues in one day in Nasiriyah, Capt Meador said he had seen more intense combat but nothing so sustained or complex. While holding a shura with elders in one village, his Marines could be fighting in the next.
He is adamant the company has already made inroads, convincing the locals that they are here to stay. Their greatest hurdle came when, contrary to Taliban propaganda, they did not up sticks and leave after an election in which few, if any, dared to vote.
The Marines first shura was a disappointing flop, with just two men accepting the invitation. But earlier this week, 20 elders turned up to sit under a canopy and air their views in an animated but often jovial conversation.
One of them, called Mirza, explained: "The Taliban said we will cut off your head, your fingers if you go to the shura. But we had to come. The most important thing is peace, prosperity and security and no civilians are killed."
"I thank you for your bravery for coming. What do you need? The Marines are here to help. We are going to be here for a long time and we all need to start to work together," said Captain Meador as he opened the meeting, knowing full well that amongst those seated around him were men, whose friends or relatives might be firing at his Marines tomorrow.