Nick is trapped halfway out the driver's side window, soon after the accident. A pool of blood shimmers beneath him, and in the reflection he sees Buck, the God Of Everything That Will Kill You, smiling back. He never knew deities like Buck existed. Nick sees him as his salvation, and his demise.
Nick has to make a choice. Either he follows Buck to the ends of the earth, or he makes a stand for himself. It's a hard decision. After all, murder on the rez is a hard thing to escape.