What does Inspector Bucket's new case at the end of Dickensian signify?

The BBC TV series Dickensian is a somewhat fanciful soap opera which attempts to fill in the backstories of a wide variety of characters from the novels of Charles Dickens, interwoven into a single narrative.

At the end of the series, the characters are all in the positions and situations from which the plots of their respective novels begin. The only exception that I could see was the police detective, Inspector Bucket.

His closing scene is in a pub, discussing his latest case with a friend. He describes having been given a murder case to solve, where the victim was stabbed through the heart yet the door of the room was locked and all the windows closed.

This sounds like a classic "locked room mystery" trope. Yet this is nothing like the actions Bucket is to undertake in the novel Bleak House. Indeed I am not aware that Dickens ever wrote a locked room story. Is this a reference to anything in Dickens, or anything else in particular? If not, do we know why Bucket alone was given an ending not in sync with his known future activity?