I'd like to try to fill the archetypes for the classic characters, but let people develop them however they please. The geek who leads the way, the mechanic, the doctor, the demolition expert, ect. 

It'll probably start off as the team departs on the cargo ship, leave room for character development, and then the sub launch and leviathan attack. They struggle along the highway to Atlantis with meager rations and low equipment supply until they finally make it there. 

Eventually the evil military guy double crosses our geeky hero and the team has to decide whether they stand with them or with the mercenaries. Fight ensues, good guys win, yada yada.

Basically, I want to follow the general plot of the movie, but with OCs and maybe a few extra details that you can't fit in a single film.