Infernal Affairs - 2002 - 7/10
AKA - Mou gaan dou // 無間道

Triad member Lau enrolls in the police academy, rises through the ranks, yet is criminal to the core.
Chan is expelled from the police academy, then joins the Triads (though he is actually undercover).
Sound somewhat familiar? Yes, Scorsese remade this in 2006 as The Departed.
(The remake is exceptional, and Scorsese, unlike most copycats, graciously credited the HK version.)
While similar to the remake, Infernal Affairs is a considerably darker experience.
For one thing, this is steeped in the ramifications of the 1997 handover to China.
The promise of “One country, two systems” swirls through the film.
Spawned a terrific prequel, then a so-so sequel. View the first two.