Daniel leads Natasha to an independent coffee shop. He orders something complicated, and Natasha orders black coffee. Daniel decides to not make a joke about it in case she thinks it's racially insensitive. She insists on paying and doesn't smile when Daniel jokes about the price of a life.
Even though Daniel resists the joke for good reasons, their respective coffee orders to reveal a lot about their personalities: Natasha is no-nonsense and just wants caffeine, while Daniel craves something rich and interesting.
They sit down at a table, and Daniel asks Natasha if she needs to be somewhere when she pulls out her phone to check the time. She admits she does, but says nothing more. Daniel feels as though he has no more bravery left to ask her questions. He wonders if he seems awkward or like a jerk to her. Natasha asks if Daniel is still happy he saved her since she's not being very nice, and he notes that he doesn't have a time machine to go back and not save her. He's aghast when Natasha asks if he would go back and not do it.
It's important to note that Natasha's phone is a tool for her to use to not connect with Daniel, even as it does keep her connected to Attorney Fitzgerald and her appointment. Natasha's question about the time machine makes sense given what the reader knows about her; it's likely a purely theoretical ask, not an emotional interrogation.
Natasha goes to the restroom, and Daniel pulls out his notebook. When she returns, she makes a joke about Daniel being a poet. Embarrassed, he thinks that his fleeting moment of déjà vu was nonsense: he'll marry a Korean American girl like his parents want him to, become a doctor, and be perfectly happy. Daniel thinks, however, that something about Natasha makes him think his life could be extraordinary, but he reasons that it's better to part ways. Dae Hyun would never be comfortable with him dating a black girl.
Daniel appears to conceptualize the future his dad has set out for him in much the same way Natasha views science and rational thought: it's the path of least resistance, with presumably the least emotional fallout. Essentially, Daniel is struggling to reconcile his love of emotion (his sense of déjà vu) with the promise of boring stability.
Daniel asks Natasha what she'd do with a time machine, and she seems engaged for the first time. Daniel realizes she knows a lot about time travel when she declares that it's complicated. When she mentions the grandfather paradox, he pretends to know what she's talking about, but she sees right through it. She explains it to him: if Daniel had an evil grandfather, he could either go back in time to kill him before his grandfather met his grandmother and then Daniel would not be born, or he could go back in time to kill his grandfather at a time when Daniel’s birth is already assured, and then he'd still make the time machine—but his grandfather would be dead. Through this conversation, they ascertain that Natasha is Jamaican and Daniel is Korean.
It's worth noting that time travel's complexity aside, it's also not real—and Natasha's apparent interest in something that's not real indicates that there's more to her than just a love of science, provable things, and rational thought. She very clearly has interest in something entirely speculative, which foreshadows her eventual acceptance and acknowledgement of Daniel's way of looking at the world. She's also very passionate about time travel, which again shows that her distaste for passion is just a front.
Daniel insists they're ignoring the grandfather paradox, and Natasha begins to explain another issue with time travel. As Natasha chatters on, Daniel thinks she's extremely cute. He can't think of anything to say when she's done, as he finds he can't truly think and look at her at the same time. He mentions a Japanese phrase to the reader that refers to the feeling of knowing that you'll love someone eventually. Daniel thinks he feels that way about Natasha, but he's sure she doesn't return the feelings.
Again, Daniel's overwhelming sense that he and Natasha are supposed to be together suggests that within the world of the novel, destiny is real and certainly has a hand in bringing Natasha and Daniel together—especially since Natasha, who claims to not believe in destiny, felt the same way.