The reason? Science! As a friend put it, Dragon plays like CSI: Kung Fu. I'd add a dash of Rashomon.
Set in 1917, it opens with kindly papermaker/family man (Donnie Yen, Ip Man) reluctantly thwarting the robbery of a general store, leaving the two criminals dead. But how, wonders the investigating detective (Takeshi Kaneshiro, Red Cliff), could a simple papermaker best a pair of convicts in combat.
In pursuit of an answer, he uses his scientific knowledge — and utilizes acupuncture to suppress his empathy for humanity — to examine the crime scene. The re-enactment from his perspective differs greatly from the one we see; he’s an unreliable narrator, but it leads him to uncover secrets in the case.
The surprises don’t end there. Dragon is as involving as it is entertaining, and Yen actually gets to act, instead of just kicking ass. He does both very well. —Rod Lott