Horatio Timeline and Summary

1.1 Horatio, who came to Elsinore for the old King's funeral, stays up late to debunk this story about the ghost of Hamlet's father appearing on the battlements. To his shock, the ghost is real.
1.2 Horatio greets Hamlet and tells Hamlet about the ghost of the dead King.
1.4-1.5 Horatio goes with Hamlet to see the ghost; with the others present, he is sworn to secrecy about the ghost's appearance.
3.2 Horatio watches The Mousetrap to see Claudius' reaction. It's hard to miss. He celebrates Hamlet's successful plan, but tries to bring his friend back to earth.
4.5 Horatio advises Gertrude that she should talk to Ophelia, even though she doesn't want to. He claims Ophelia's condition is causing unrest among the populace.
4.6 Horatio receives a letter from Hamlet saying he's not in England, but headed home.
5.1 Hamlet and Horatio reunite in the palace graveyard. Then they talk about death.
5.2 Horatio warns Hamlet not to take part in the "friendly" duel Claudius and Laertes have arranged.
5.2 Horatio offers to commit suicide and die with Hamlet, but Hamlet says he should stay alive to explain the whole sordid story instead. Horatio lives to tell the story.