All of Edugyan’s novels—from her 2004 début, “The Second Life of Samuel Tyne,” set in rural Alberta in the late nineteen-sixties, to “Half-Blood Blues,” short-listed for the Man Booker Prize in 2011, to “Washington Black”—are historical fiction, yet they rarely give the sense that history is their main concern. The brutalities and injustices of the past supply Edugyan, the Canadian child of Ghanaian immigrants, with situations that she uses to crack open the human psyche and expose the tender, tangled material within. After a faltering start with “Samuel Tyne,” about a rather awful family and their similarly unpleasant neighbors, Edugyan hit upon the theme that seemed to unlock the form of the novel for her: friendship, particularly friendship between men.

In “Half-Blood Blues,” a jazz band comprising various races and nationalities seeks its fortune first in Berlin, then in Paris, as Europe comes under Nazi rule. The novel’s narrator, Sid, is an American bass player of modest gifts. The band’s young star, the trumpet player Hieronymus (Hiero) Falk, is the child of a German mother and a black father, a bona-fide genius whose parentage renders him a vulnerable, stateless person in his homeland. Sid envies Hiero’s talent and sees him as a rival in love. “Half-Blood Blues” burrows into their relationship: Sid’s exhilaration when Hiero’s playing brings out the best in his own, resentment when the younger man gets the lion’s share of the praise, and, very occasionally, compassion for Hiero’s lonely, rootless condition. Like it or not (and Sid often doesn’t), the two men belong to each other, as brothers. “That kid was blood to you,” insists the band’s drummer, with whom Sid has an equally contentious yet close bond. “Don’t tell yourself it was any different.” Similarly, at the end of their road together, Titch tells an accusing Wash, “I treated you as family.” Considering how some people treat their families, though, that might be the problem.

Until Titch comes along, the closest Wash has to a family is Big Kit, a strapping woman who takes him under her protection when she finds the other slaves bullying him. The sole refuge Big Kit can offer him, however, is a suicide pact; only death, she’s convinced, will return them both to the African kingdom from which she was kidnapped. Still, Wash loves her, and when he goes to work for Titch he never has the chance to speak with Big Kit again. The savagery of the plantation—which has been given the ironic name Faith—is both physical and emotional; a slave might lose his tongue for back talk or he might lose, for no reason at all, the only person who means anything to him. Even the fascination Wash finds in scientific inquiry and the Cloud-cutter project exacts permanent costs: his face is disfigured when he’s burned by a hydrogen explosion. The Wildes themselves are subject to their clan’s legacy of betrayal, coldness, and cruelty, all funded by the sugar that Faith produces and that Titch, a covert abolitionist, refuses to eat. Titch’s depressed cousin, hobbled by the burden of a miserable childhood, arrives to deliver a fateful message and then, in an act of stupendous selfishness, takes Wash with him into the brush and commits suicide, enjoying the grim privilege denied to Big Kit. Titch knows that Wash will be killed on the mere suspicion of involvement in a white man’s death, so the pair flee Barbados in their airship.

Here Edugyan transforms “Washington Black” from a Grand Guignol of slavery’s horrors into a lush, exhilarating travelogue reminiscent of Jules Verne, full of improbable events and encounters but with a splinter lodged in its heart. Titch crashes the Cloud-cutter into a ship captained by twin brothers on a shady mission. The ship deposits Wash and Titch in Virginia, where they meet an amateur forensic pathologist who uses his creepy hobby as a cover while operating a station on the Underground Railroad. The fugitives now reach a crossroads. Titch plans to travel on to the Arctic, to the remote research outpost where his revered father (“a Fellow of the Royal Society, you know, and the recipient of both the Copley Medal and Bakerian Lectureship”) has been both reported dead and rumored to be still alive. He urges Wash to join a pair of escaped slaves on the path to freedom in the North. Wash refuses.

“Not an evening since that fated night in Virginia have I not revisited the choice,” the eighteen-year-old Wash confesses. At Faith, he learned what “a man who has belonged to another learns very early”: to watch the master closely. Titch may have taught Wash to read, introduced him to the wonders of science, and given him credit for the illustrations in a paper submitted to his beloved Royal Society, but habits die hard. The boy pays minute attention to Titch’s moods. “How painful all this was proving to him,” the boy thinks. “It was obvious the death of Titch’s father had crushed him, and now the possibility of that father living still was crushing him. It strained his wildest hopes, opened up the wounds of his grief.” This is a degree of scrutiny learned in fear, but under changed circumstances it resembles nothing so much as love.

“When a man sends ten thousand troops to attack you, it means he has a crush on you.”

Does Wash love Titch? Not romantically, but in some other sense that he barely understands—the way, perhaps, that a son might love a father. Back at Faith, Big Kit told Wash that to be free is to “go wherever it is you wanting,” and yet the prospect of separating from his mentor fills Wash with “a panic so savage it felt as if I were being asked to perform some brutal act upon myself, to sever my own throat,” an imaginary violence unsettlingly reminiscent of the real punishments dealt out at Faith. Slave owners often justified themselves by claiming that blacks were children incapable of looking after themselves, but Wash, at thirteen, really is a child, and now Titch, the only person he has in the world, seems to be trying to escape from him. It isn’t always brute force that binds us to other people, and the invisible compulsions are what interest Edugyan most. The pair board another ship, this one headed for the Arctic, and when at last they enter the polar region Wash leans over the railing to see, “in the passing black waters, eerie, exquisite cathedrals of ice.” The submerged shapes (“how sad, how sacred!”) might as well be the attachment that now defines his young life, as dimly comprehended and as perilous.

Edugyan has a chameleonic knack for adapting her novels to the periods in which they’re set. If you didn’t know otherwise, you would assume that “Half-Blood Blues” and “Washington Black” were written by different authors. The earlier novel is languid, slangy, and smoky, its characters confined to night clubs where they banter and rib one another about sex and booze and how badly they played the night before. In “Washington Black,” Edugyan suggests the diction of another time without attempting to replicate it. “I was astonished to see these habitats,” Wash reports, describing the first time he sets eyes on a group of igloos; “fear cut through me, as though I was gazing upon the site of a resurrection.” Despite the outlandishness of his exploits, the stops on Wash’s journey have none of the allegorical quality of the towns featured in Colson Whitehead’s “The Underground Railroad.” There’s a meticulous realism to Edugyan’s rendering of each place that this grand, old-fashioned, overstuffed plot passes through, from “London streets with their laughter and dirty-cheeked children, their ill-lit alleyways alive with the bright hiss of rats,” to the North African desert, where a sweltering Wash notes that “the air felt very tight, full of salt.” The voice that Edugyan has conjured for her narrator is articulate, precise to the point of fussiness, yet subject also to fits of melancholy, emotional agony, and ravishing transports at the glories of the natural world. Wash is a nineteenth-century man of science, with a résumé of travels and adventures to rival Charles Darwin’s and a harrowing past that will not leave him be.