When the Engineer learns about Weyland 's intentions , he decapitates David and uses his head to beat Weyland to death .
On the Engineer ship , he has David talk to the Engineer ; Shaw interferes , and Weyland orders her subdued and shot if necessary .
When the Engineer learns about Weyland 's intentions , David decapitates David and uses David 's head to Weyland Weyland to death .
On the Engineer ship , he has David talk to the Engineer ; Shaw interferes , and Weyland orders her subdued and shot if necessary .