Jim Clarke is Helen Clarke’s husband. She brings him to the Blackwood house after it burns to try to get Merricat and Constance to come live in the Clarkes’ house. Later, she sends him back with Dr. Levy to try again, but both times the sisters hide. Jim seems to mostly want to help the Blackwoods to satisfy his wife, rather than because he genuinely cares about them.
The timeline below shows where the character Jim Clarke appears in We Have Always Lived in the Castle. The colored dots and icons indicate which themes are associated with that appearance.
...She comes around to knock on the kitchen door, convinced that the sisters are inside. Jim Clarke is with her, and she tells him that the sisters misunderstood the villagers the night... (full context)