Harper presented a number of documentaries for the
BBC, including a July 2006 documentary on
Volunteer Ministers in
Scientology for
BBC Radio 5 Live. She then worked as a producer and reporter for
Channel 4 News before joining
ITV News Anglia in 2010 as a staff reporter. Harper successfully submitted her short story "Wild Swimming" to
Stephen King's
Bazaar of Bad Dreams short story competition. The winning story then featured King's 2016 anthology
Six Scary Stories. That March, Harper signed a two-book deal with
Mulholland Books for the publication of her debut novel
The Binding Song, a thriller set at the fictional HMP Halvergate in Norfolk, in 2017. This was followed by her second crime novel
The Death Knock in 2018. However, she felt her first two novels, set in the "Norfolk Noir" genre, were too close to her day job, motivating her to go into historical fiction. Historian
Dan Jones introduced Harper to Head of Zeus (a
Bloomsbury Books imprint), through which Harper published her first historical fiction novel
The Wolf Den in May 2021. Set in ancient
Pompeii, the novel follows Amara, a young woman enslaved in the city's
Lupanar. She cited Robert Knapp's
Invisible Romans,
Mary Beard's
Pompeii, and
Alison Cooley's
Pompeii and Herculaneum as some of her sources when conducting research for the novel. ''The Wolf's Den
debuted at #1 on The Sunday Times'' paperback fiction list, won the
Goldsboro Books Glass Bell Award, and was shortlisted for Page Turner of the Year at the 2022
British Book Awards. It was also longlisted for the Historical Writers' Association's (HWA) Gold Crown Award. This was followed by a sequel
The House with the Golden Door in 2022, which entered the top 10 on the bestseller list. The third and final installment
The Temple of Fortuna was published in 2023. Antonia Senior of
The Times called it "one of the best historical fiction trilogies" since
Hilary Mantel's
Wolf Hall. In 2022, it was confirmed Harper would reunite with Head of Zeus for her next two novels: ''Boudicca's Daughter'' and an untitled novel about
Fulvia,
Mark Antony's wife. ''Boudicca's Daughter
was named one of the best historical fiction books of 2025 by The Sunday Times''. In 2024, Harper signed her first children's book deal with
DK Children for a middle-grade trilogy. ==Personal life==