In Mayfly, the story shifts back to Cassie's point of view. She has run away from the Buick and the Silencer only to succumb to her injuries. She is now buried in a snowbank in the outer metal shell of an old car, slowly freezing to death.
Cassie has a hard time figuring out if she is still alive or if she's already dead. Her mind wanders across the course of her life and how exactly she got here. She spends a few days in the snowbank and apologizes to Sammy in her head for never coming to rescue him. Cassie thinks she will die here.
Suddenly, Cassie wakes up to find herself bandaged and warm, her head still in a fog. She realizes that someone has cleaned, bathed, and taken care of her. She is slightly creeped out by this and concerned who exactly she could be dealing with.
Cassie is very weak and can barely sit up. She meets Evan Walker, a lumberjack type. He is the one who saved Cassie. She is instantly attracted to him, but at the same time, embarrassed by her predicament.
Cassie explains how she got in the snowbank, from the beginning of the Arrival to the present day. She is worried about her leg, but Evan reassures that it won't need to be amputated. Evan goes out for a while and then brings her some clear broth.
Evan debates whether the soldiers who killed her father and took her brother were human or Others. Evan decides that they must be Others due to the Eye, or sound wave, that they unleashed to kill the adults. Cassie worries about the lamp that Evan lights, thinking it will attract Others.
Evan goes out to patrol the grounds and hunt again, before helping Cassie take a bath. He tells her that he thinks they should leave for Wright-Patterson or Fort Knox when the weather gets warmer. Cassie shares her desire to go back to Camp Ashpit where her father died and trace her brother's movements from there.
Cassie realizes that Evan read her diary when he mentions the Crucifix Soldier. This unsettles her. Evan explains that he understands why she did it. She identified the soldier with the soldiers who took Sammy. Evan then kisses Cassie. She tries to resist after the first kiss, but then gives in. Evan confesses that Cassie saved him, in ways she doesn't realize.
The appearance of the mysterious Evan is very foreboding. It is worrying that he does not seem to have a solid backstory and that he so willingly saved Cassie. It is unprecedented in the harsh world Cassie has become used to.
There is some foreshadowing when Evan lights the lamp without thinking that the Others will see it and come for him (159). This is the first sign that Evan may not be everything that he seems to be. He may be a human allied with the Others, or even an Other.
Another odd behavior of Evan's is that he goes out every morning to hunt but never brings anything back. Cassie, in her weakened state, is entirely dependent on him and doesn't recognize yet that this is suspicious.
Evan and Cassie have both developed instantaneous deep feelings for one another. It's difficult to understand where this emotion comes from, other than their mutual beauty and struggle in this new, dangerous world. Evan seems to be damaged, as he says that Cassie saved him, despite her being unconscious, wounded, and barely knowing him.
Cassie is very tortured with the knowledge that her baby brother might have been taken by the Others, that she may have sent him, or rather, given him away to them willingly. It is impossible and horrible for her to contemplate.