What happens at 11:50 pm after the party in Every Day?

On Day 5999, A is in the body of Nathan Daldry. A logs into Justin's email and finds out about a party that night, not too far from where A is. He attends as Nathan, where he befriends Rhiannon. A does not usually hijack people's lives like this, but everything is different after meeting Rhiannon. He gets caught up in the evening, and does not get to Nathan's car until 11:15. He will not make it home in time. A changes bodies every day, and it seems that this happens at midnight.
At 11:50 A pulls over on the side of the road. He closes his eyes, and for Day 6000 wakes up in the body of Roger Wilson. Meanwhile, we find out that Nathan was woken up in his car by police officers. Nathan had no explanation other than being possessed by the Devil. Nathan contacts A via email. He goes to the press with his story, and while others come forward claiming similar experiences, Nathan becomes ostracized at school. He continues to press A for answers via the email address, and the two eventually meet.