I think the weakness in this story is its length. At 92 pages, with several illustrations, it is really more of a short story than a novella. This certainly would have been nothing more than a chapter in any of the other Delaney books that I have read.
An orphan gets a job as a prison guard in the town's notoriously haunted castle prison. One night, the most unenviable of prison chores falls to him, to feed the prisoner in The Witch Well.
4 STARS based on length alone. It is a 5 STAR story with the usual strong Delaney imagery.