This is a scene from the movie "The Shining" by Stanley Kubrick(video link below) https://www.youtube.com/watch?v=qVoLTp46nP8
WENDY: And you're gonna lose. And I'm gonna get you - you betta run fast! Look out - I'm coming in close. All right?
- To finish a contest or competition in a particular position or place (as in first, second, third, etc.). I didn't expect to come in first or anything, but finishing last is pretty disappointing.(source: Farlex Dictionary of Idioms)
This definition doesn't make sense though because she is still chasing him and the race isn't over.