An interesting way to start off the story would be that the thing on the Pork Chop Express gets to the cab and incapacitates Jack Burton, causing the truck to run off the highway. The heroes stop to help and see the thing running back to San Fran. They hear Jack mumble "Gracie Law" before losing consciousness and being taken off by the ambulance crew. Then, this group of haphazardly-thrown-together-would-be-heroes is free to back track to Gracie (perhaps learning the story that has gone before), who may or may not already be captured by the thing in its bid to bring back Lo Pan or work some other mischief. Maybe it first needs to bring back the storms: Thunder, Lightning & Wind--or maybe they're already loose and not really destroyed at all. Perhaps Mao Yin also figures in this plot, but then you start getting all the movie characters in there; except Egg Chen, who is off on a long vacation. Tracking down Egg for some vital information or equipment could be a nice side trek. An interesting twist would be if the story shifted to Chinatown in another city, perhaps New York:
Chinatown - Wikipedia, the free encyclopedia
Chinatown - Wikipedia, the free encyclopedia