the show begins with the watchmen talking about how they think they saw the ghost of the late king hamlet.
HAMLET AND HORATIO
Hamlet comes to his mother and uncles wedding in all black. He then procedes to act out and be very distant with everyone there.
WATCHTOWER
Once Hamlet is alone he breaks down and talks about how his father just did and yet nobody seems to care. This is the first time we have the theme of revenge come into play.
THE TRUE STORY
After a few scenes of ophelia getting talked to horatio, who we find out is hamlets best friend, tells hamlet that while he was nightwatching he saw his father's ghost. Hamlet asks to see where his father was seen.
After a scene with ophelia and her brother, leartes, hamlet went to the watchtower to see for himself.
After everyone runs and leaves prince hamlet alone. The ghost of his father comes to him and tells him about how he was murdered by his uncle, who is now prince hamlets father . The ghost then says he can't have everlasting peace and he will be "doomed to walk the night" if hamlet doesn't avenge his death. This is when the theme of revenge comes very clearly into play.