You and Clint had been mind controlled and taken by Loki, when Clint was sent to get Loki back from the ship you begged him to take you with him. Even being mind controlled couldn't keep you two apart.

Clint blow up one of the engines and told you to stay on the plane while he went to go get Loki back.

Loki came back but Clint didn't, you asked Loki what happened. He told you Clint had severed well but he was no longer with us. Anger filled your body and you swore revenge on shield, for taking the man you loved from you!