We can’t be completely certain, but based on the conversation between Charlotte and Dolores, it certainly seems like the host implanted in the Charlotte body is none other than Teddy, one of Dolores’s closest companions from the park. He may even be the only other host Dolores trusts entirely–so it would certainly make sense for him to be given such an important job.

It is, however, important to remember that that trust may not go both ways. Dolores and Teddy’s relationship came to a brutal end back in Season 2 when Teddy’s deeply ingrained morality began to struggle against the violence and bloodshed that Dolores was inflicting on both humans and hosts. He “killed” himself as a way out–but, naturally, being a host, escape was never going to be that simple. If it is Teddy inside Host Charlotte, there’s probably going to be some really complicated emotional baggage dug up somewhere down the line as he and Dolores are inevitably forced to confront their shared past.