What words and phrases help create this mood?

Lennie Turned his head and looked off across the pool and up the darkening slopes of the Gabilans. "We gonna get a little place," George began. He reached in his side pocket and brought out Carlson's Luger; he snapped off the safety, and the hand and gun lay on the ground behind Lennie's back. He looked at the back of Lennie's head, at the place where the spine and skull were joined.