The Dragon Missile

Sima Jun is a killer working for a corrupt lord whose orders are followed without question or hesitation. When the lord suffers from a life-threatening boil on his back, he is told by the Imperial doctor that a herb called "Longevity Rattan" offers the only cure and is grown in a remote village by a herbalist named Tan.
Sima Jun is sent on a mission to get the herb and return it before it's too late (seven days). A jealous aide saddles Sima Jun with six other fighters to accompany him so that they can steal the herb when they get the chance and race back to the capital so the aide will get the credit. Sima Jun doesn't trust the six and none of them trust each other.
(Source: TMDb)