Why do you suppose the author refers to hamlet and his father?

The author begins the novel with the words "Marley was dead", to make sure the readers are convinced of the fact because he feels that it has a distinct bearing on the case. The author says that there would be nothing remarkable in Hamlet's father strolling in his own rampart at night unless he was already dead. Similarly, there would be nothing special about Marlow visiting his old friend, unless he was already dead. the comparison between Hamlet's father and Marlowe can be read in different ways. It may be to contrast the purpose of their visits. Hamlet's father visited Hamlet to ask him to take revenge, making Hamlet sin in committing patricide in killing his step-father; while Marlowe visited Scrooge to save him from his own vile. The purpose of Hamlet's father is selfish, while Marlowe's is unselfish and generous.