I’m not that familiar with the work of director Johnni To, but this Hong Kong film, set entirely in a hospital,  is decidedly fun and tense.  There are cops, there is, at least for most of the movie, only one (injured) bad guy who is under guard in a hospital (waiting for his accomplices to come and spring him loose), one seriously stressed surgeon  and the ever-present feeling that something bad is on its way.  (Subtitled.)

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