Samantha Finn's History
Samantha was a member of the Peace Corps in Central America. One night, her entire infirmary got slaughtered by what seemed to be a demon. Having been rescued, she quit the program and joined the squad. Sam then met Riley Finn in South America in her first firefly. According to her, it took Riley a year to get over his ex-girlfriend Buffy Summers, but they eventually got married and forged a duo of demon hunters. The wedding itself was held in a military chopper, just before it dropped into hostile territory. They had commandeered the helicopter from a local guerrilla squad.
With four months of marriage, they were tracking Suvolte demons through Central America, until it went to the Hellmouth to spawn, so Sam went to Sunnydale with Riley. They suspected its eggs were being sold in the black market, and there was a dealer in town who called himself "the Doctor." During the mission, she met and counted with the help of Buffy as well as the Scooby Gang.
Some time later, Sam and Riley attempted to settle down in Iowa, intending to take over half of his parent's farm, and attempt to be safe and even have children. She did, however, have reservations about giving up the excitement of top-secret missions, and supported her husband to assist Buffy infiltrating the Twilight Group as her double agent.
Years later, Sam led a follow-up team to the U.S. Military escort mission for Dr. Walt Zane's expedition in Suriname, which had lost contact with their base. Her team faced the same problem, and Riley went after his wife, but was captured by the local tribe of vampires. In the jungle, Sam eventually met Faith Lehane, who was in a mission for Deepscan to find him, and they joined forces to rescue Riley. As they approached the camp he was held, she recognized the Slayer as the woman who had had sex with him during a body swap, when he thought he was with Buffy, his girlfriend at the time. Faith then attempted to apologize to her, but Sam refused it, explaining it wasn't her place to give her any kind of absolution, but she could be useful helping her in the mission. The rescue mission was successful, and the couple was finally reunited.
After the return of magic, Sam and Riley were present in Rome and Buenos Aires to deal with the attacks of a centipede demon and a giant horned gorilla demon, provoked by the opening of portals through the Restless Door in power of the Mistress, the Sculptor, and the Soul Glutton.
During the Supernatural Crisis Act, Sam and Riley were brought to the Safe Zone in order to convince Buffy to renounce her Slayer powers in exchange for her freedom. She was resistant, but they explained that, despite they had their own concerns with the way the Government was dealing with the supernatural, they had been deployed in San Francisco, Rome, and Buenos Aires, seeing in first hand the crisis and its effects. Buffy trusted their judgement, and accepted having her powers absorbed.
Sam and Riley then visited Buffy after she was free from the Safe Zone, and revealed their plan to help the Scooby Gang and save the supernatural. They offered Xander and Dawn to leave the country, and fake I.D.s to Buffy and Willow. Noticing the uncertain of the group in dealing with this mission while powerless, Sam quickly convinced them they were more than her magic, and they all entered the mission. She drove Riley, Buffy, Willow, and Faith back to the Safe Zone, so they could invade the headquarters and discover about the Pandora Project.
After the Scooby Gang defeated Joanna Wise and her Project, the group feared their treason would put them in jail, so they allowed the credit to go to Sam and Riley, as they were government agents. The couple was present in President Malloy's public announcement, in which he declared the policies regarding the supernatural were reviewed under the supervision of "the heroes who exposed the conspiracy, Riley and Samantha Finn," and exalted their "distinguished record of service" to the country. By this time, Sam had the military rank title of specialist.