General Alak is the central antagonist of Anna and The King - a film based loosely on the musical The King and I, although some of the characters involved are true many of the events depicted are either fictional or modified somewhat for dramatic effect.
General Alak was a high-ranking member of the military in Siam (which is now known as Thailand) during the reign of King Mongkut and Siam is under siege from what appears to be a British-funded coup d'état against the King, using Burmese soldiers. Mongkut sends out his brother Prince Chaofa General Alak to investigate.
However, it turns out that Alak is the man behind the coup and he turns on and kills Chaofa, as well his entire regiment (he poisoned the regiment and tried to do the same to Chaofa, however Chaofa sensed betrayal when Alak did not drink the wine or eat the rice - prompting Alak to chase him down and shoot him).
Alak then flees Siam into Burma where he summons and readies his troops to invade Siam and kill the King and his 58 children.
With Anna's help, the King manages to hide his children and his wives in a safe place, then he goes with the few soldiers he has to face Alak.
The King and soldiers place high explosives on a wooden bridge high above a canyon floor, as Alak and his army approaches. The King orders his "army" to stay back and rides to the bridge with only two soldiers. Alak, in front of his army, confronts the King on the bridge.
Anna and Louis then orchestrate a brilliant deception from their hiding spot in the forest: Louis uses his horn to replicate the sound of a bugle charge, as Anna "attacks" the area with harmless fireworks.
The ploy works as the Burmese, believing the King has brought British soldiers, retreat in a panic.
Alak attempts to recall them, but his efforts prove to be futile.
Alak stands alone and one of the King's men requests permission to kill the traitor, but the King refuses, saying that Alak shall have to live with his shame.
As the King turns to ride back to Siam, Alak picks up a gun and aims at the King, but the explosives are detonated by one of the King's men (who spots Alak's betrayal just as he was about to pull the trigger), blowing the bridge to pieces, and Alak along with it.