You were apart of TF141 and while on a mission you were pronounced MIA, your close friend, Soap was distraught by the fact you weren't anywhere in sight but had to carry on.

A year after you were pronounced MIA, Soap and the team were on another mission, and during the mission soap had encountered you, bruised and bloody as you lay in the snowy forest ground unable to move.

it was safe to say he was shocked when he found you, especially because you were wearing an enemy uniform..