Disclaimer: Don't own anything of Buffy or Stargate Atlantis
Warning: Character death
As childhoods go, Meredith Rodney McKay had one that was as far from normal as you can get. At barely five years old he was given an IQ test and it was revealed he had an IQ of 200. An unquestionable genius. Despite not wanting to let his skip so much of his childhood, his parents had no choice. At twelve he was in college and thanks to a little bomb and the CIA, he was doing 'projects' for the US government. By eighteen he had seven degrees, two of them being PH D's, and by then his IQ was 257. He was working with, living in, devoted to the US. Rodney hadn't even spoken to his parents since they tried to tell the Canadian government he was 'fragile' and needed supervision, saying that there was a fine line between genius and insanity, and he didn't care.
While attending universities, working for the US and, a few other governments, Rodney also did several patents that both revolutionized the world and made him quite rich. At twenty-two, Rodney, created a way to make clean energy, and while still on a experimental stage it earned him a Noble Prize. Something he cherished beyond everything.
By twenty-four he had four more degrees and two more PH D's. He was approached and told about a device discovered in Egypt decades ago. He went to Colorado and had his entire life changed forever, for there he met Samantha Jane Carter. They met, fell in love and married all in a week. They worked on the project for two years, during that time Sam gave birth to twins: Isabella Elizabeth and James Alexander McKay and was giving birth with a third when Daniel Jackson arrived. Thus missing the Stargate being activated and the first team going through. Lucius Albert was born on the very day Daniel did it.
A year later, Rodney,Sam, and Jack stepped through onto Abydos, and Rodney met Daniel for the first time and felt an instant connection but ignored it as Sam was everything. Several events later had all of them back on Earth completely changed. Rodney had one interesting talk,aka talk-threat, later with the President and he agreed for SG-1 being Rodney, Sam, Jack, Daniel and Teal'c. A new life had begun.
During a freak accident that caused Sam to become a host to a Tok'ra, they eventually met Martouf/Lantosh, and eventually Rodney and Sam would take him to their bed and hearts.
Three years later Daniel lost Sha're, his wife, killed by Teal'c to protect Daniel. The team all surrounded him, protecting him and comforting him to the best of their abilities. Rodney decided they needed a vacation so he bought a island in the Caribbean. Then he bulldozed his way threw the US government until they agreed. Which wasn't that difficult as no one wanted Rodney upset. So Rodney, Sam, Daniel, Jack, Martouf/Lantash and the children went to the island and stayed there until Daniel healed. Which took about five months and falling into Jack's bed.
Once they returned, Daniel began searching for Shifu, the son of Sha're. While Rodney began to working on the governments view on gays. Like DADT, Don't Ask Don't Tell. Making comments like: How can I work for a government that views part of my relationship as wrong. Also commenting on how Canada, his home country and England both accepted it. So perhaps he should move there. Word eventually reached the President and Joint Chiefs. They quickly got a vote across that rid the military of a arcane law and then gave Rodney more money;just in case. Daniel and Jack were very thankful.
Months later, Sam gave birth to Julianna Catherine. Less than two months after that, Sam was forced to shoot Martouf to save several people. Also to prevent losing both of them, Rodney let Lantosh in. Grief stricken and devastated, Sam and Rodney just wanted to be alone but the Tok'ra refused. Saying Lantash had to come with them. Even when Lantash told them he wanted to stay on Earth they insisted. Hammond told the Tok'ra they wouldn't force Lantash to leave and Rodney would NEVER go with them. So they were forced to leave. SG-1 and the children retreated back onto the island and mourned. When Lantash told Rodney and Sam that Julianna was Martouf's as she had too much naqaudah in her blood, otherwise, they were happy. A part of him lived, though Rodney and Sam would never, ever tell anyone as the NID and others would do anything to get their hands on her. Something they would never allow, hell they freely admitted that they would blow up the Earth before allowing anyone to turn their little girl into an experiment.
As time moved on they were able to let Martouf go and accept the fact that he was gone. Even when an attack by a gou'ald named Ares caused Lantash to willingly sacrifice his life a year to the day of Martouf's death, they survived. They were finally in a place where they were happy, though Lantosh's death caused them to seriously discuss quitting. But they didn't, though, though they really should have. For two months after Lantash's death, SG-1 was on a mission, Sam's last for a while as she was pregnant. They got captured by Enyo, seeking revenge for her father's death. She tortured them all for days before they were rescued, but it was to late for Sam and thus for Rodney. Sam died on May 15 at 4:50, Rodney killed himself at 4:55. They were buried together and with much fanfare. The Asgard even attending what they regarded as the greatest lost of the age. For the Asgard regarded Rodney as smart as them, truly a member of the Fifth Race. And Sam was mourned by them as well.