At the beginning of the poem, the sleepless poet, who has suffered from an unexplained sickness for eight years (line 37), lies in his bed, reading a book. A collection of old stories, the book tells the story of Ceyx and Alcyone. The story tells of how Ceyx lost his life at sea, and how Alcyone, his wife, mourned his absence. Unsure of his fate, she prays to the goddess Juno to send her a dream vision. Juno sends a messenger to Morpheus to bring the body of Ceyx with a message to Alcyone.
The messenger finds Morpheus and relays Juno's orders. Morpheus finds the drowned Ceyx and bears him to Alcyone three hours before dawn. The deceased Ceyx instructs Alcyone to bury him and to cease her sorrow, and when Alcyone opens her eyes Ceyx has gone.
The poet stops relaying the story of Ceyx and Alcyone and reflects that he wished that he had a god such as Juno or Morpheus so that he could sleep like Alcyone. He then describes the lavish bed he would gift to Morpheus should the god discover his location. Lost in the book and his thoughts, the poet suddenly falls asleep with the book in his hands. He states that his dream is so full of wonder that no man may interpret it correctly. He begins to relay his dream.
The poet dreams that he wakes in a chamber with windows of stained glass depictions of the tale of Troy and walls painted with the story of The Romance of the Rose. He hears a hunt, leaves the chamber, and inquires who is hunting. The hunt is revealed to be that of Octavian. The dogs are released and the hunt begins, leaving behind the poet and a small dog that the poet follows into the forest. The poet stumbles upon a clearing and finds a knight dressed in black composing a song for the death of his lady. The poet asks the knight the nature of his grief. The knight replies that he had played a game of chess with Fortuna and lost his queen and was checkmated. The poet takes the message literally and begs the black knight not to become upset over a game of chess.
The knight begins the story of his life, reporting that for his entire life he had served Love, but that he had waited to set his heart on a woman for many years until he met one lady who surpassed all others. The knight speaks of her surpassing beauty and temperament and reveals that her name was "good, fair White". The poet, still not understanding the metaphorical chess game, asks the black knight to finish the story and explain what was lost. The knight tells the story of his fumbling declaration of love and the long time it took for the love to be reciprocated and that they were in perfect harmony for many years. Still the narrator does not understand, and asks the whereabouts of White. The knight finally blurts out that White is dead. The poet realises what has occurred as the hunt ends and the poet awakes with his book still in hand. He reflects on the dream and decides that his dream is so wonderful that it should be set into rhyme.