Childhood
Andrew McCarthy was born forty years and some change ago to a small Catholic family in Belfast. His father was a member of the Royal Ulster Constabulary, while his mother was mostly content to stay at home. His childhood was fairly average; he went to a small elementary school until he was eleven, and after passing his eleven plus he went into a local boys' grammar school. He was rather good at science, maths and English.
Being a Catholic in a largely Protestant school didn't help Andrew's popularity much, and this led to him being bullied by a small group of them. James Stillman was the worst culprit, a small but fairly quick and strong lad from the year above who improved his self image by beating the crap out of the unpopular kids in the school with as large an audience as possible. This changed around the time Andrew reached his thirteenth birthday. News of his birthday spread through the school, and Stillman was there to administer the traditional "birthday beatings"; one punch for each year of the victim's life, and one for good luck. The first punch was to the body, just below the chest, winding Andrew before he could even start to fight back. Twelve more punches followed, leaving Andrew with a couple of loose teeth, a broken nose and a cracked rib. Stillman paused the beating, had two of his friends stand Andrew back on his feet and hold him in place.
Just before he was able to finish off, however, Andrew was able to break one arm free and throw a punch at his tormentor. The punch landed on Stillman's jaw, just left of the chin, and sent the young man flying about ten feet. "One for luck," he growled as one of the teachers finally managed to intervene. Andrew and Stillman went to the hospital together; Stillman was unconscious, with a broken jaw and a cracked skull. Andrew's nose didn't heal straight, and has been a fairly distinguishing feature on his face ever since. No one bothered him at school after that event; they decided the reason he didn't fight back before wasn't that he couldn't, but that he didn't want to hurt anyone as seriously as he had just then, after receiving the worst beating he'd ever taken.
Military Life
Andrew left school at the age of fifteen, and joined the Royal Marines. Training was hard, even for one as strong as he, especially when he had to try and hide his full strength, but he enjoyed the military lifestyle and hadn't ripped a door off of its hinges in over a year. Not accidentally, at least. He was a fairly decent shot with a rifle and very good with a pistol, though in both cases he had to make sure to let recoil affect his shots at least slightly. He passed out two months after his sixteenth birthday; just in time to fight in the Falklands War.
Andrew's tour in the Falklands wasn't pleasant by any stretch of the imagination; he lost several friends over the two and a half months of intense fighting that made up the short, bloody war. In one mission, at least, he was able to help his friends with his strength. They were on a mission to take out AAA defences on one of the smaller islands when they were discovered. After a short firefight, the Argentinians grew tired of using regular infantry and sent a lightly armoured recon vehicle at the squad. Had they been armed with anti-armour weaponry, it wouldn't have posed a problem, but assault rifles were of no use. Andrew hid, primed a grenade and ran at the tank while the gunner's back was turned, punching through the armour and dropping the grenade. He ran back into cover, his hand covered in blood - his own - and petrol, with only a second to spare before the tank exploded. "That never happened, understand me?" he insisted of his somewhat stunned squadmates. They agreed, and no more was said of the incident. His strength came in useful in several other conflicts, though each time it was only used in an emergency and under the condition that nothing would be said about it later.
During his time in the Marines, Andrew fought in almost every major conflict Britain has been involved in, led men, fought with friends and watched a fair number of them die. In 2004, at the rank of Warrant Officer 2, he retired from the Marines and, not liking the direction he saw Britain going in, decided to move abroad. Using his military pension, he acquired a green card and moved to New York.
The Shit Hits The Fan
Two years passed, during which time Andrew worked in an Irish pub and worked towards gaining citizenship. He was working that fateful night when Peter Petrelli went nuclear. The city was in chaos, and between that and the situation, Andrew decided to help as many people as possible, lifting rubble off of people who'd been trapped. One of those people was a regular at the pub he was working at, a man named Brian.
"Christ, I owe you one," Brian said, sighing with relief.
"Keep this between us, and we're even," Andrew replied.
Not long after came the Registration act. Brian was mostly in favour of it, which led to an argument with Brian in which he said quite bluntly, "So I'm stronger than most. Why the fuck should I have to tell everyone in New York about it? Long as I don't go ripping the doors off of bank vaults, what difference does it make how strong I am?"
Brian agreed not to turn Andrew in, and thus far hasn't. Two months ago, Andrew McCarthy was sworn in as a US citizen, and while he has to be more careful than ever with his strength, he hasn't given himself away yet. He attends a Jujutsu class, and has done for three years, as a means of keeping fit, though he doesn't take part in any martial arts competitions - he'd consider it cheating.