Alias Grace: oh, I noticed its existence a while ago, I just am dreadfully crowded in rl terms right now!

Jeremiah: a good take on the trickster trope, I thought, which is why I'm glad the show (or the novel) don't reveal what was really going on with him. He appears to be helpful to Grace (and the sole male character who isn't creeping on her at any point, though in all fairness Dr. Jordan only does so in his own imagination and behaves professionally in reality; I feel the AV Club reviewer, for example, is harder on him than he deserves), but there is a question mark about it. Which is as it should be with tricksters. Incidentally, I do think he wanted to help her by setting up that seance, that to him, it was a clear set-up because he wanted to give Grace the chance to (fakedly) declare her innocence so Dr. Jordan would be pushed to write a favorable report. That Grace doesn't do so and what happens instead is one of the great ambiguities of the show. If she's faking the entire Mary Whitney possession, why do so in a way that makes her situation worse, not better? (If Dr. Jordan had written any report on this at all, as he tells the Reverend, Grace would have been either put back into the asylum which she hated, because it would have made her sound insane; 19th century spiritualism wasn't an accepted law defense. Or, if Jordan's report had expressed the opinion that Grace was faking it, it would have gotten her tried for the murder of Nancy - which she never was, she'd been on trial solely for Kinnear -, which "Mary" had just admitted to.) Otoh, all that "Mary" says is so pointed that it's hard to believe Grace wasn't stage managing. Then again, "Mary" as a seperate persona developed by Grace's subconscious due to all the abuse she'd suffered would fit with modern pyschology. (And seems to be the theory Jordan mostly believes when he quits.) And because it's Margaret Atwood, you can't even completely exclude that the supernatural explanation - it truly is the ghost of Mary Whitney speaking - is the real one. Like I said, I dig the ambiguity.

To bring this back to Jeremiah: when he's reading Grace's palm in her youth, he seemingly starts out cheerfully faking it as a way of banter, and then gets surprised by truly seeing something about her future. Which could indicate Jeremiah, in addition to being a trickster, is another trope occasioally appearing in fantasy, the conman/woman pretending to have supernatural gifts who is surprised by the discovery she/he does have indeed supernatural gifts. In which case he could have intended to fake hypnotize Grace and ended up actually hypnotizing her.