The Guest
A family mourning the loss of the eldest son, Caleb, who was killed on active military service, are visited by a fellow soldier, "David" who served in the same Special Forces unit. Polite, friendly and helpful, David is invited to stay on, even sleeping in Caleb's old room. He tries his best to help the various family members with their problems, but the methods he uses become more and more extreme. Until the people who set up his experimental unit come looking for him...
Basically, Captain America as a Slasher Movie Villain. David is an All-American Super Soldier, highly trained and much stronger and tougher than any normal man. He's also been conditioned to kill everyone who might compromise his identity. Even people he genuinely likes.
One intersting twist is that rather than the US Military being responsible for David, it's actually a private corporation who were running the experiment.
Good performances from the whole cast and some excellent action sequences. Although I did chuckle at one of David's victims who obviously attended the Prometheus School of Running Away.
10/10