Kit meets John Holbrook on the ship on the way to Wethersfield. He is going to Wethersfield to study with Reverend Bulkeley. He is kind to Kit, and she finds him mild but pleasant. She has enough trouble on the journey to Wethersfield, especially when she jumps into the water to retrieve Prudence’s doll.
… John Holbrook had been about to warn her. There was something strange about this country of America, something that they all seemed to share and understand and she did not. She was only partially reassured when John said, with another of those surprising flashes of gentle humor, "I shall sit with you at supper, if I may. Just to make sure that no one's food gets curdled." (Ch. 1)
John Holbrook spends a lot of time with the Woods, and Judith eventually becomes sweet on him. It is not until later that the family realizes that it is not Judith he wants to see, but the quiet and also mild-mannered Mercy. With Kit and Judith vying for every young man’s attention, everyone forgot about Mercy!
Those great listening eyes were fastened on the face of the young man bent over his book, and for one instant Mercy's whole heart was revealed. Mercy was in love with John Holbrook. Faster than thought the shadows clarified Mercy again. Kit glanced hastily around the circle. No one else had noticed. (Ch. 11)
John Holbrook is a good friend to Kit in Wethersfield, even though she is “forever astonishing him.” He is patient and gentle, and she likes listening to him read. Despite this, Kit is not in love with him. Judith is, but Mercy is the one whose affections are returned. Eventually, Kit ends up with Nat and Judith with William Ashby (whom she loved before Holbrook came), and Mercy and John can marry.