What happens to Mr. Bumble?
We first meet Mr. Bumble in the workhouse where Oliver is born. His role is beadle of the workhouse but his attitude towards the orphans is one of cruelty and neglect. In Chapter 3, for instance, Bumble calls Oliver a "naughty orphan which nobody can't love."
We see very little of Mr. Bumble once Oliver has run away from Mr. Sowerberry's and gone to London. He returns briefly in Chapter 17 when parish business takes him on a visit to London. There, he sees an advertisement placed by Mr. Brownlow which asks for information on Oliver Twist, in return for five guineas. Motivated by the money, Bumble heads to see Mr. Brownlow and tells him how Oliver was born of "low and vicious parents" and is incapable of displaying anything other than "treachery, ingratitude and malice." Of course, Bumble knows exactly where Oliver is but does not reveal his whereabouts to Mr. Brownlow.
It is not until Chapter 37 that we see Mr. Bumble again. The narrator tells us that he has married Mrs. Corney and become the master of the workhouse. Life, then, seems to be going well for Mr. Bumble. But, in fact, he is miserable in his marriage to Mrs. Corney because she is so domineering and, even worse, he misses his role as beadle: "“Strip the bishop of his apron, or the beadle of his hat and lace; what are they."
In one key incident, Mrs. Bumble throws a bowl of suds at her husband in front of the workhouse inhabitants. Bumble's reaction gives us a glimpse of how he feels about his life:
"He looked dejectedly round, and slunk away; and, as he reached the door, the titterings of the paupers broke into a shrill chuckle of irrepressible delight. It wanted but this. He was degraded in their eyes; he had lost caste and station before the very paupers; he had fallen from all the height and pomp of beadleship, to the lowest depth of the most snubbed hen-peckery."
Finally, in Chapter 53, we learn the long-term fate of Mr. Bumble. He and his wife are fired from the workhouse and end up in such a poor state of poverty that they are forced to live there as inmates. By giving this fate to Mr. Bumble Dickens makes an important point about the nature of being cruel and heartless towards others. In short, the message is that you reap what you sow.