First, let me state that I think it is a good beginning to a story.
That said, and I feel bad saying this because it's just a personal preference, but I'm not exactly what you would call the biggest fan of third person omniscient. But, an actual piece of advice, do something to mark off what is an actual thought that a character has. For example,
That's it Alex decided.
The "that's it" is an actual thought that Alex thinks, in his head, no? If it is, then it's helpful to mark it off as such, with italics or some such. So, it would become:
That's it, Alex decided.
Sorry if I sound mean or anything, that just jumped out. But, as I said, seems like it could make a good story.