Frannie Langton, the singular and single-minded heroine of Sara Collins’ highly accomplished debut novel, is a former slave who is accused of stabbing to death her employer and his wife. At the start of the book, in 1826, she sits in her cell awaiting her fate.

She explains that she can’t save her own skin because, despite being found with blood on her hands, she has no recollection of the crime. With more certainty and more clarity, she goes on to state what kind of tale she is about to tell: “This is a story of love, not just murder.”

Her story has its true beginning back in Jamaica on a slave plantation. Like Sweet Home in Toni Morrison’s “Beloved,” its name — Paradise — is a sick joke. At a young age, Frannie is taken from the slave quarters to work in her owners’ house. Her mistress, Miss-bella, teaches her to read and write. Her master, Langton, a depraved scientist, turns her into his scribe and forces her to record the findings of his barbaric practices.

When dramatic events bring Langton’s “little colonial experiment” to an abrupt end, Frannie is shipped across the Atlantic to London and given as a gift to George Benham, supposedly the finest mind in England, and his beautiful and eccentric French wife, Marguerite. Still in servitude, Frannie nevertheless comes to realize she has swapped “an iron cage for a gilded one.” This is due to Marguerite, who shatters her belief that “every white you’ll ever meet either wants to tame you or rescue you.” She becomes Frannie’s friend and companion, inviting her to salons and soirees and speaking candidly and intimately with her.

Inevitably, yet also incredibly, this special relationship between mistress and servant develops into an illicit sexual one. Warned by Marguerite that some things cannot be brought into the light, head-over-heels Frannie cries, “Then let it be done in the dark!” But in time suspicion wreaks havoc, betrayals cause rifts and murder rears its ugly head.

“The Confessions of Frannie Langton” is large, lavish and gutsy, a skilled and intoxicating mash-up of slave narrative, gothic romance, whodunit and legal thriller. Collins — who lives in London and is of Jamaican descent — pays careful attention to historical detail while at the same time ensuring her reader stays immersed in her emotional drama and invested in her full-bodied characters.

Throughout, there are pleasing echoes of Jean Rhys’ “Wide Sargasso Sea” and the stylish historical fiction of Sarah Waters. Collins is overfond of metaphors, but fortunately she exercises restraint in other areas, withholding secrets for as long as possible and dropping stray bombshells when we least expect them.

This novel keeps us guessing right up until its frantic last act. What is beautifully clear throughout is its protagonist’s ardent yearning. As Frannie declares, “Life is a brief candle, but love is a craving for time.”

Malcolm Forbes has written for the Times Literary Supplement, the Economist and the New Republic. He lives in Edinburgh, Scotland.