This is the first "Gone Wrong" episode I have ever seen and laughed from start to finish. "A Christmas Carol" is being staged by a group of totally inept actors and stage hands. Actors must go on with the show even when props fail, characters don't show up, stage hands are visible, people fall out windows or through floors, etc.
Derek Jacobi does an excellent job as Scrooge keeping it all together or all not together. Henry Lewis plays a 200-pound Tiny Tim after he accidently crushes the smaller actor who was Tiny Tim with a stage prop. There also was a modern party scene that I totally did not understand, but maybe I needed to watch the other "Gone Wrong" episodes first.