Dew, a young computer programmer, takes refuge in Chiang Mai. There, she is reunited with Ton, whom she met during her aunt's funeral, and discovers that he is the love of her life. Sadly, Ton is plagued by a brain tumor and passes away prematurely.
Unfortunately the movie The Letter is not yet available on HBO Max.
| Directing | Pa-oon Chantornsiri | Director |
| Production | Nonzee Nimibutr | Producer |
| Production | Duangkamol Limcharoen | Producer |
| Writing | Kongdej Jaturanrasmee | Screenplay |
| Production | Somsak Techaratanaprasert | Executive Producer |
| Production | Nonzee Nimibutr | Executive Producer |
| Camera | Naruphol Chokanapitak | Director of Photography |
| Production | Ek Iemchuen | Production Designer |
| Editing | Patamanadda Yukol | Editor |
| Sound | Boyd Kosiyabong | Original Music Composer |
| Sound | Chatchai Pongprapaphan | Original Music Composer |
| Costume & Make-Up | Thawatchai Petchvara | Costume Designer |
| Production | Phalathon Siraksa | Casting Director |
| Directing | Chinoret Kamwandi | First Assistant Director |
| Production | Ratchana Nimchareonpong | Production Manager |
| Art | Kamolsak Khumsin | Art Direction |
| Sound | Suraprom Pinyosub | Sound Recordist |
| Sound | Thanapong Boonyachai | Sound Editor |
| Crew | Sunit Asavinikul | Mixing Engineer |
