Movie 1 is basically a retelling of the 1st 8-9 eps of season 1. They cut out a few scenes to condense it into a 2 hour movie. A small backstory was added to show the discovery of the Abyss, but it wasn't anything enlightening or worth mentioning. It doesn't omit major plots or scenes, but just a small recap of the episodes. To be honest, if you have season 1 there is not reason to watch the movie unless you just want to say you have watched it. Considering this was only part of season 1 I would that Movie 2 covers the restof season up until ep 13 following the same pattern as Movie.