This is a Magnificent 7 modern day AU, where they're a SHIELD team. I have most the characters' backgrounds sorted, just need a plot!
Chris Larabee: Army Special Forces, captured in Afghanistan, thought to be dead, three years later, escapes/maybe rescued. Comes home to find his wife had recently remarried (wanted to do something other than killing her off)
Buck Wilmington: Grew up with Chris in New Mexico, they joined the Army together, he never gave up on Chris, never truly believed he was dead. Tony Stark's escape gave him fresh hope that his friend might be alive.
Ezra Standish: (this is my favourite one) Maude was exiled from Asgard to Midgard, where she married a human. She's always telling Ezra she's going to restore his 'god given gifts'[snerk]. Ezra is captured sneaking around the bifrost site in New Mexico.
Vin Tanner: Chris met Vin while they were both in hospital at the US military hospital in Germany. Chris after his escape, Vin for wounds from an IED. After they come home, Chris removes himself to his family's ranch in New Mexico, and offers Vin a home and a job as long as he needs it.
Nathan Jackson: A doctor at the hospital in New Mexico Thor first showed up, he knows more than he should due to his drunk friend Darcy telling him more than she should.
Josiah Sanchez: Obadiah Stane's head of security, who realized too late what his boss was up to. Arrested after the events of IM I, he's trying to atone for what he's done.
JD Dunne: Hotshot pilot, crop duster as a teenager, joined the Air Force, trained to fly choppers. Think Murdoch from the A Team except sane.
Sound like it has potential? It's definitely been entertaining me the last few days!