Mood in Oroonoko is connected to the characters' relative states of freedom. When Oroonoko is in his home country, for instance—before his capture—the mood is rather optimistic and lighthearted. Although Oroonoko and Imoinda have been separated by the king, they both maintain hope that they will belong to one another entirely in the future. Even after Oroonoko is captured, he maintains optimism, which the mood of the novella reflects. When his captors realize who they have in captivity and pledge to release him, Oroonoko trusts that they will hold true to their word. Though the behavior of the colonizers is clearly suspicious, both Oroonoko and the reader maintain faith at this point that a happy ending is still possible. Chivalric romances often—though not always—resemble fairytales in that they end happily, with the hero satisfied in his quest despite suffering loss along the way.
As Oroonoko asks to be freed again and again yet remains in captivity, both the reader and Oroonoko begin to doubt the trustworthiness of his captors. At this point, the story veers into the realm of tragedy. A bleaker, desperate, and more hopeless mood settles onto the narrative, culminating in Oroonoko being cut into pieces. Though he dies with his honor intact, such a death is hardly the one Oroonoko would have wanted.