Who reminds her of Augustus even though they aren't related.(Unless u think that would be a strange plot twist where her twin seperated-at-birth sister's step brother turns out to be Augustus's twin brother). Then Tris will teach Hazel how she leaves and Hazel does the same. Then, like any twin story they wish to switch lives on a shooting star (they can't on there own because of the cannula) and it works then Tris wakes up in the morning annoyed because she can't breath and is very weak. Hazel wakes up strong and is amazed that she doesn't have to have little numbing up her nose all the time.