The movie revolves around a crew which get infected by some alien stuff, might also be radiation or something. One by one they get superstrenght and the ability to transform into (metal) weapons. I don’t know much, all I seem te remember is the end: Only a man and a woman survive and on their way back (to Earth?) she gets pregnant. As times evolves (spacetravel takes long) the baby grows and I seem to remember them staring at Earth as they get closer. He holds her while he makes a comment about how every body will understand now (something like that). She turns around and slams his chest as he is still holding her. The camera zooms in on her womb and shows the baby is growing claws, thus revealing the man is mutated after all, he just controlled the killing urges. End of movie.