The woman in white confronts Vader, saying the Imperial Senate will not stand him attacking a diplomatic ship.
Vader retorts he knows she's a member of the Rebel Alliance and orders her taken away.
He then orders an officer to send a distress signal that all aboard were killed. He'll use Princess Leia to find the secret rebel base as she is his only lead—guess he's already choked his way through those prisoners we saw a moment ago?
Another officer tells Vader that the Death Star plans are not aboard the ship, but that a life pod was jettisoned with no life forms.
Vader believes the plans are aboard and orders a detachment to retrieve them.