(Warning: Multiple Drive Spoilers)
So the driver (Ryan Gosling) has just killed gangster Bernie Ross (Albert Brooks) and driven off into the Los Angeles sunset, badly stabbed, but still alive. He took a little bit of the stolen mob money to get himself a ticket out of the country and go meet up with his brother who resides in Bangkok. There he gets back into the family business of drug smuggling which he tried to escape in the first place. Early on in the film, his brother (who is pretty much a scumbag) is killed and he is forced to find out who is responsible and deal with his crazy mother (Kristin Scott Thomas) who has herself returned to make sure vengeance is done. You won't blame him for running away from his shit house crazy family to Los Angeles for those few years to work as a mechanic once you are introduced to them.
So Drive & then Only God Forgives is the perfect double feature if you like blistering violence or just want to gaze longingly at Mr. Gosling for 190 minutes. And somehow, there happens to be less dialog in Only God Forgives. I think Gosling & Nicolas Winding Refn must have had some sort of bet going on.
And if you don't agree with my excellent theory, well, enjoy yourself anyway. We're all adults.