They must piece the entire puzzle together. There is work associated with reading a tragedy because a reader must open his or her mind in order to make the character's actions plausible. The reader must feel as though the events could happen. What's more, the reader must be able to somehow connect with the characters and their reactions.
In Hamlet, or other tragedies, there is no hope that the characters will survive their hideous death. The reader must follow within the loops and curves that the play offers in order to connect action with reaction and vice versa.
A tragedy always reveals the main character's weakness. In this case, Hamlet's weakness was his vulnerability and his indecision. He wouldn't listen to his associates when he had the chance. He also didn't act promptly when given a chance to avenge his father's death. Had he killed his uncle in the offset of the play, it is arguable that some of the deaths towards the end of the play may not have occurred. Hamlet needed proof that the ghosts were telling the truth. Since he didn't believe them and had gave his uncle the benefit of doubt, the tragedy unfolded.
When Hamlet transforms into a raging madman because of his father's death, the reader knows for certain that people will die at Hamlet's hand. It is uncertain whether the uncle will be killed because such irony is a calling card in tragedies. The reader may surmise that everyone will die except the uncle and that Hamlet may live to grieve over his love, Ophelia.
Another point of contention is set up early in the play. There is the issue of Hamlet's mother. The ghost expressly said the his mother shouldn't be harmed. However, Hamlet doesn't listen. He feels it necessary to question his mother and accuse her. Had he not been in her chambers accusing her of contributing to her husband's death, Hamlet would not have killed.
Ophelia is also warned in this play, another mark of someone who is either going to die or who will play a role in someone else's death -- as in the case of Hamlet himself. She is warned to stay away from Hamlet. Of course, as the reader knows, she won't listen.
Therefore very early in the tragedy the reader is handed a roadmap that will somehow spell out the fate of all of its characters. It is up to the reader to consider the possible outcomes and piece them together. A tragedy such as Hamlet, however, is filled with so many twists and turns that just about any tragic ending is plausible. The reader must play a game in determining whether their guesses will turn out to be realized in the play. Will Shakespeare through us all for a loop or will this play simply verbalize an ending that the reader has already surmised. An artist like Shakespeare, always has a surprise ending at hand. In such case, the ending of the tragedy is usually not fully realized until its ending. Shakespeare sought, in many sense to not only act out passions associated with people in his time, but to also entertain and shock. In this case, the tragedy is not for the passive reading experience because the author must always be one step ahead of the reader.
Shakespeare, William. Hamlet. New York: W.W. Norton…