Hulu's Washington Black is based on Esi Edugyan's 2018 novel of the same name, and, as is the case with every book-to-screen adaptation, it makes its fair share of changes from its source material.
Where Edugyan tells the novel in fairly linear chronological order, the series, run by Selwyn Seyfu Hinds and Kimberly Ann Harrison, adds a flashback structure, alternating between inventor George Washington "Wash" Black's childhood (where he's played by Eddie Karanja) and adulthood (where he's played by Ernest Kingsley Jr.). The show also adds entirely new characters, like William McGee (Edward Bluemel).
But the biggest change from book to TV show is undoubtedly the show's ending, which goes in a very different direction from the original novel's.
What happens at the end of Washington Black?

In the novel, Wash and his lover Tanna (Iola Evans) travel to Morocco to find Christopher "Titch" Wilde (Tom Ellis), the scientist with whom Wash fled Barbados when he was a boy. Wash thought Titch died in the Arctic, since he walked into a snowstorm with barely any gear or supplies. However, Titch survived and continued his scientific research and inventing.
When Wash reunites with Titch, he confronts him about how the scientist abandoned him all those years ago. Yet Titch isn't remorseful in the slightest, choosing instead to reflect on his own youth and the ways in which he harmed his late cousin Phillip. Realizing that Titch is trapped in the past, Wash walks out into an oncoming sandstorm. Edugyan leaves his fate ambiguous.
The show features Wash and Titch's confrontation, but not Wash's disappearance into the sandstorm. Instead, it sees Wash finally build the airship he's been developing all season long, which he and Tanna use to sail to his late mother Big Kit's (Shaunette Renée Wilson) native Dahomey. There, he connects with the Agojie warriors and learns about his mother's life before enslavement. He and Tanna settle there, get married, and have a child. They also continue their adventures, flying to the Solomon Islands so Tanna can reunite with her own mother.
It's a much more hopeful and optimistic ending than the novel's. There, Wash heading into the sandstorm reads as a mirror to Titch walking out into a snowstorm, suggesting that perhaps, like Titch, Wash is losing himself in the pains of his past.
The series, on the other hand, imagines a future where Wash thrives after his conversation with Titch. Crucially, he and Tanna both get to reconnect with the pasts that had been denied them. As a mixed-race, white-passing woman, Tanna was consistently told to push down any part of her that tied her to the Solomon Islands. Meanwhile, Wash didn't find out his guardian Big Kit was his mother until long after her death. Still, he gets to connect with her through his journey to Dahomey, joining his present (and his child's future) to her past.
The massive difference between the show's ending and the novel's speaks to the show's efforts to find joy in a period setting defined by racism towards and oppression of Black people.
In an interview with Newsweek's H. Alan Scott, Washington Black star and executive producer Sterling K. Brown discussed these efforts, saying, "This project came to me before American Fiction. But American Fiction actually talks a lot about how it seems most of Black stories that are for mainstream consumption have to do with Black pain, have to do with Black trauma, right? So I thought, how awesome would it be to take this historical context but to still illuminate, [and] highlight, joy, hope, faith, love, etc."
And nowhere does that sense of joy and hope come through more clearly than in Washington Black's final moments, where his many dreams — of freedom, of finding love, of inventing something great — are all coming true.