Ten years later, Irene hasn't forgotten the girl (Natasha) who saved her life when she was a security guard. One of the case officers, Lester Barnes, stopped to tell her that the girl had called to say thank you. Irene didn't know what for, but it saved her life. She'd planned to commit suicide that night but instead, she listened to the Nirvana album again. She thought of the girl and called a suicide prevention hotline. Eventually, she found therapy and medication.
Natasha's phone call very literally saved Irene's life, which reasserts the novel's insistence that human connection has the power to save and heal people. Simply being connected to other people because of a cosmic connection wasn't enough for Irene; it was only through an active reach that she lived.
Irene followed her childhood dream and became a flight attendant. She keeps an eye out for lonely passengers and comforts those who are afraid. Now, she checks the plane for anyone who might need her attention. She passes a young Asian man engrossed in writing, and notices a young black woman with a big Afro, the ends dyed pink. Irene stops in her tracks when she recognizes the girl who saved her life. She's wanted to thank this girl for ten years.
Just as Natasha paid Irene's kindness forward by calling to say thank you, Irene now pays Natasha's kindness forward by caring for other lonely people. The fact that Natasha's hair is dyed pink suggests that ten years later, she's found a middle ground between frivolity and rational practicality.
Once the plane reaches cruising altitude, Irene approaches the black woman and hesitantly tells her about that day in New York. Irene tells her about the message she left to thank her, and suddenly, it seems very important that this woman remember. Finally, the woman says her name is Natasha, and she remembers. The Asian man peers over the seat, his eyes full of love. Natasha meets his eyes and says, "Daniel."
When Natasha and Daniel come back together as a result of a connection Natasha made, it shows that Natasha's transformation into someone who values human connection was the most important transformation of the novel. It's unclear where the plane is going, but it's very clear that destiny was at work here, and Natasha and Daniel did just need scale to make it work.