Secret Avengers #1 (2014)

In Dubai, a high ranking Roxxon executive is entering his personal apartment with two women, one dark-haired, the other blond, all the while bragging about his security. He tries to kiss the blond one, revealed to be Valkyrie, who gets very agitated and breaks hers and Black Widow's cover. After slamming the man into a book shelf, the two heroines arm up and face off against Roxxon security forces. Captain Steve Rogers crashes through the window to back them up and manages to secure a box containing an unknown glowing object. As Sharon Carter arrives with their ride, Valkyrie apologizes for blowing their cover, though Rogers assure her that no one knows who they are. As they take off, two masked men close by report to their boss that someone has beaten them to their prize.

On the Secret Avengers' transport, Beast determines that the object they recovered is a distant cousin of the Serpent Crown. Rogers theorizes that it may be a part of a set. Furthermore, the former observes that its parts are moving, as if it was alive. Rogers tells him to do whatever he can to figure out how Roxxon acquired it. He then heads up to the bridge, where Sharon is flying their craft. She asks him if he's comfortable with running a black ops team. He answers that it's similar to how things were back in the Invaders and it's best to do some good. After some talking, they kiss.

At Roxxon HQ in Wilminton, Delaware, Moon Knight and Ant-Man infiltrate the place and disable two guards. As Ant-Man shrinks down and enters a vent, he comments that this isn't what he expected when he was asked to become an Avenger.

Flashing back to two weeks ago, Rogers approaches Moon Knight, offering him a place on the team, saying that black ops work is the perfect for a skeptic like him. A week later, Rogers approaches Ant-Man, giving him a one-time offers to help redeem himself.

Once the two spies access the computer systems, they send all the intel to their team. From the data, they learn that a Roxxon operation on Mars was shut down a month ago for no reason, at the same time that the word "Serpent" Crown came out.

Meanwhile, the same mysterious men are tailing the Secret Avengers. Over the radio, their unknown leader promises to join up with them soon.

Two nights later, Rogers has his team assembled at a former H.A.M.M.E.R. facility. He explains to them that they have to go to Mars. To get there, they have a modified Kree warship. As they board, Rogers asks Valkyrie if she is comfortable with going to another planet. She replies that it can't be as bad as going undercover. Rogers tells her that he doesn't know, but they need someone with her power set for this. Once they are prepared, War Machine asks Rogers what happened to the man he sent to Mars. The answer is that he lost contact with him.