this will be the best. I mean it.
MI's with a twist at the end.
At the end, when you have to get to the sub, you get in but Odell, realizes that the sub will not start. Also, you have a another problem. As Odell starts to fix the sub, the Combine are coming. So, with the use of a mounted gun (yet to be picked, a OICW is a good choice), you hold them off. After you have done that, Odell fixes the boat. Then the sub rides away and Path of (the) Borealis plays.