Born in Massachusetts in 1756, the only daughter of Thomas March, an innkeeper, and his wife, Ann. Her mother died when Merrick was five, and afterward her father raised her alone.

In 1778, Merrick and her father became involved in General George Washington’s Culper Ring. It was at this time that Merrick met and became involved with a man named Cassius Amador, who was a British spy. In 1781, a jealous would-be-suitor, who Merrick had rebuffed many times, betrayed the cause - and Merrick. King George’s red-coats attacked the March’s Inn in the early hours of the morning, killing her father and taking Merrick captive. The jealous traitor knew Merrick was to meet with rebels that night, so the red-coats - after beating and raping Merrick - tied her up with a musket at her breast. The intent being to threaten her with death if the rebels did not surrender. And then they settled in to wait and spring their trap. After hours of silent and discreet struggling, Merrick managed to work one bloodied hand free from the ropes, her finger just able to reach the trigger on the musket. From her vantage point near the window, she watched and waited, and when the moon rose high in the sky, and she was certain she heard hoofbeats coming nearer in the distance, Merrick closed her eyes and pulled the trigger, the bullet shattering not only the night, but her breastbone and killing her instantly - and as was her last thought, hopefully warning Cassius of the ambush. With their captive dead, and still no sign of the rebels, the red-coats set fire to the inn and left. When she awoke later, covered in her own blood but no longer wounded, Cass was at her side to explain to her that, like himself, she was Immortal.

She left Massachusetts with Cassius, training with her lover as they traveled, spending time in Baltimore and Philadelphia among other places, learning not just the Game from him, but about war and strategy. Some 80 years later, in 1861, the Civil War erupted, and the pair joined the Union in fighting. Four years into the war, Cass sent word to Merrick, who had been working with Allan Pinkerton and the Union intelligence Agency, that they had to leave immediately he wouldn’t say why on paper, but he’d arranged passage for them both to head further west. Enroute to their rendezvous, Merrick was confronted by an Immortal she didn’t get his name, as he charged her without a word of challenge. It was her first fight in the Game, and to say she was not scared would have been a lie. But she was also confident in her teachings, and as she drew her sword she felt as if it were an extension of her body, just as Cassius had instructed her time and again in his soft and patient tone. The stranger fought hard, thrusting and swinging wildly, and wearing himself down, while Merrick controlled her breathing, her movements, and each stroke of her sword. She took his head, and unbeknownst to her, as the Quickening struck her body, a Creek Indian hunting party watched on. When Merrick came to, she was in the Creek camp, surrounded by their elders awed by the woman who was struck by lightning over and over and lived, they took her back to their camp intending to nurse her back to health. To their amazement, she recovered quickly - though not quickly enough to meet Cass. Admittedly, being apart from her teacher for the first time was a bit scary, but Merrick decided to stay with the Creek people for awhile.

Visiting England for the first time in 1904, Merrick meets and is the lover of poet and fervent pacifist, Alfred Noyes. Two years later, long after they had parted company, Noyes published his romantic poem, The Highwayman, much of which mirrored Merrick’s mortal death.

Joined the Secret Intelligence Service - later known as MI6 - in 1910. Her duties mainly focused on gathering intelligence on the German government. By the time WWI broke out in 1914, Merrick was deep in enemy territory. When the war was over, she stayed on, honing her skills, which came in handy when WWII broke out in 1939. Merrick, working with the Soviets against the Nazis, befriends fellow Immortal and spy Rebecca Kirk at this time.

At the end of the war Merrick started her own espionage school, with a front as a boarding school in Eastern Europe. She ran said school until 1960, at which point she returned to the US for the first time in almost 70 years, only to find herself once more fighting in another war. This time as one of 5,000 American women who served in Vietnam. This war would change Merrick...the things she saw, the things she and others did, the absolute horror of it all, left a bad taste in her mouth for war. When she and her platoon were slaughtered in 1974, Merrick quietly left Vietnam, disappearing for four years.

In 1978 she surfaced in Haven, Maine, where she met Immortal Clayton Bailey. The pair became fast friends, as close as siblings, and spent five years together.

She resurfaced 11 years later in Scotland.

When Captain Trips hit, Merrick was running a private security company that employed veterans. She split her time between London and New York, where she had homes. She was engaged - a first for her - to a man named Charles, one of her partners in the security company. They were in Florida, looking at wedding venues when Charles got sick. After his death, overcome with grief, Merrick ignored the dreams she was having for as long as she could. But it was clear that a new war was on the horizon, and so she picked a side and headed to Boulder, Colorado.