In short, Scrooge starts Crachit's day with the shock of his life. When Cratchit arrives to work "eighteen minutes and a half" late, Scrooge treats him with the same malevolent demeanor he has "for many a year," and as Scrooge is scolding and poking at Cratchit causing him to back away from him with fear, Scrooge gives him the shock of his life by telling him that he is going to raise his salary " which causes Cratchit to tremble and consider knocking Scrooge down with a ruler and screaming for someone to get a strait-jacket, for he thinks Scrooge has gone insane.
Do you mean Scrooge?
Lucky old Bob Cratchit arrives for work the day after Christmas to find a different Scrooge! At first, because he is precisely eighteen minutes late, Scrooge doesn't seem to have changed and appears all ready to give poor Bob a torrent of verbal abuse. Then, he seems to remember himself and his new ways and starts to smile. He prepares a bowl of lovely warm punch for them both and says they will sit down together for a chat about raising Bob's salary! Lucky Bob must have wondered what he and his family had done to deserve such a change of heart. It seems that Scrooge has done enough to produce a change of heart just in time to save his soul as he is already quite old. We get the impression that he will live long enough to enjoy a few more years helping the Cratchit family.