Before that scene Will was just trying to sleep by covering the window and this time he even dragged a table in front of it to cover the whole light:
That is the time Rachel comes to Will's room due to the complains of other resident of the hotel:
And then Will told the whole story of how he fabricated evidence to help convict a pedophile he was certain was guilty of murdering a child to Rachel. When he asked for her response she said:
Rachel Clement: I can't judge. There are two kinds of people in Alaska: those who were born here and those who come here to escape something. I wasn't born here. src
Rachel Clement: I guess it's about what you thought was right at the time. Then, what you're willing to live with. src
Which suggested she is also escaping from her past and she found Will's action justifying too and we see in the next scene that she end up in his bed. Sound quite normal, people confirming each other end up in same bed.