The Colonel

ผมไม่อยากเป็นพันโท

Also known as Pom Mai Yak Pen Pan To, I Don't Want To Be a Lieutenant

A Thai intelligence officer infiltrates the enemy's military forces of Chiang Riang by assuming the identity of a murdered colonel who was also a double agent. The murdered colonel, married to Lamduan, worked for the government's Central Bureau while also being an informant for Red China and working to help the local People's Army.