Dark Skies - Season 1 Episode 8 Hostile Convergence

Loengard's wife Kim decides that she cannot miss her sister's wedding in Denver and sneaks away from John while he meets with one of the few people who know his terrible secret. The man that Kim's sister is planning to marry is Rob Winter, but he isn't what he appears to be ... he's a Majestic agent. During the course of his assignment, Rob really does fall in love with Kim's sister and in the end, kills the people sent to harm Kim and her family instead of doing the job that he was sent to do.