Training Day is an intense film that illustrates how fragile a grip humans have on the notion of what is right and wrong.
Jake Hoyt (Ethan Hawke) is a rookie police officer looking to make the narcotics squad led by Alonzo Harris (Denzel Washington) under the Los Angeles Police Department. However, Alonzo has his own plans and has chosen Jake to be part of his solution to a problem involving $1 million that he owes to the Russian Mafia. As a cynical Alonzo abuses his authority and does anything he wants in the name of "protect and serve", Jake grows increasingly uneasy with his new partner's approach that eventually results in a showdown.
What makes the film work is Alonzo's descent into the depths of depravity. At first, he offers a logical reason for any action he performs. As we learn more, it becomes clear that it's Alonzo's familiarity and rise from a world he despises (and one that despises him) that ultimately drags him down a path of abuse. He is a police officer who is unable to arrive at a higher ground and behaves just like the thugs he wishes would kill themselves off. His viewpoint ultimately ends up being self-fulfilling.
Denzel Washington takes on a different kind of a role in this film (in contrast to similarly intense films like The Siege, The Bone Collector, and The Hurricane) and he essentially steals the show. Ethan Hawke is well cast as a naive cop looking to "make it big". The pacing and direction by Antoine Fuqua is kinetic. There is enough of a plot and unexpected things happening to keep the film interesting.
The movie touches upon the hint of a corrupt regime where leaders in the ranks of police act like feudal warlords. Whether this is a correct characterisation of the LAPD or not is debatable, but it is within the realm of possibility. The moral that absolute power corrupts absolutely should not be taken lightly, and this film illustrates that no one is immune.