Summary

The film starts slightly before the game, on the Harbinger. Everyone who's played the game will know a lot of bad stuff happens there, with the main character ending up on Peragus. With the help of Kreia, Atton, and of course T3-M4, Kane Dolan - a former Jedi - escapes Peragus on the Ebon Hawk, just as Darth Sion and his minions come for him.

So the Exile is faced with two issues: first, someone has placed a hefty bounty on his head; second, the Sith - former Jedi who have fallen to the dark side of the Force - have returned, and seek the death of all Jedi, exiles or otherwise. Kane is forced to become a Jedi once again, in order to take down the Exchange in the second half of the film, and to eventually take on the Sith.

Characters

Main Characters
Kane Dolan/the Exile
Kreia
Atton Rand
The Last of the Handmaidens
Mira
Bao-Dur
T3-M4
Goto
HK-50s

Supporting Characters
Darth Sion
The Apprentice
Atris
Handmaiden Sisters
Zez-Kai Ell
Carth Onasi
Dol Grenn
Visquis
Hanharr
Twin Suns
Zhug Brothers
The Gand
The Champ
Hussef
Vogga the Hutt

And that's about it. I'll update this post if I think of anything to add. If you have any questions, post them here or in the Hexology thread on the KOTOR Movie Forums.