FOR a best-selling writer of thrillers, Tom Harper presents a couple of mysteries himself. These concern exactly where he lives and his real name.

A press release promoting his new novel declares that Tom lives in York, while the jacket of the book puts him in New York. This one is explained by a simple typo.

“Perhaps it seemed more interesting than the reality,” says Tom. Whatever, it will be corrected on the next edition. Tom definitely lives here and not over there.

As for the puzzle of his name, Tom Harper is really Edwin Thomas. As he had already written a series of historical novels under his own name before switching to time-slip thrillers, he needed a pen name.

Tom derives from Thomas, which is the easy bit. And he owes the Harper in part to an editor.

“He had this thing about readers looking along a line of books and not wanting to commit straight away, but they run out of steam before they get to the end of the alphabet. So he reckoned that the best letters were between C and L. I came across Harper in a book of children’s names, and I liked it because of Harper Lee, and because I am part Welsh and harpers are Welsh storytellers. And it also fell in the right place.”

So Tom Harper it was.

Tom wrote three historical novels under his own name, and is now on his fourth time-slip thriller.

“I liked writing about history,” says Tom, 34, who studied modern history at Oxford. “But my editor wanted me to try writing modern thrillers.”

As a compromise, the editor suggested time-slip thrillers, which let Tom write about the past and the present. His latest such thriller, published this week in paperback by Random House, is Secrets Of The Dead, which opens with a murder in a villa on the coast of Montenegro.

Abby Cormac, a former investigator for the International Criminal Court, now does a desk job for the EU in Kosovo, where she witnesses the murder of her diplomat lover and is herself nearly killed. Returning to London, shot and shaken up, she tries to piece together what happened, and gradually the man she had known and loved emerges as someone else altogether.

This present-day mystery is connected to a secret hidden for centuries and allows Tom to write a parallel murder mystery set the Roman Empire of the fourth century. This is wrapped up in the history of Constantine, who was acclaimed emperor here in York, and the persecution of Christians.

Tom studied Constantine at university. Modern history at Oxford begins in 285AD, he says, almost the starting point for the ancient part of his novel. “I thought Constantine was fantastic, such an interesting historical figure and a man who achieved so much.”

Tom’s first time-slip thriller was Lost Temple, which he describes as “my love letter to Indiana Jones”. He was a huge fan of the films as a boy.

He now has seven novels to his name, having been first published at the age of 24 – “I was incredibly lucky” – when The Blighted Cliffs was runner-up for the CWA Debut Dagger award. He has spent most of his working life as a writer, apart from three years in pensions services, about which he has little or nothing to say.

Next up is a time-slip thriller about Plato, the classical Greek philosopher. “It’s the world’s first thriller about Plato. No one’s written one before and there may be a reason for that,” says Tom, wryly.

He plans his novels carefully, with spreadsheets mapping out the past and the present. Tom enjoys the research and always travels to the places where his characters will be.

“If I write a scene without having been there, it’s much harder and takes much longer. If I can actually picture the place and see the person, see the sky and the panorama behind them, then they just slot in.”

Secrets Of The Dead took him to Pristina in Kosovo.

“It wasn’t what I was expecting. I thought it would be like a bombed-out shell. But it’s not like that at all. It’s a very exciting city, full of young people, with café bars on the street and there seems to be lots of life and money. Yet while I was there, four people were shot dead not far from where I was staying.”

While mapping out his two plots, Tom spotted parallels which helped to tie the story together. For instance, when he visited Camp Bondsteel, the US Army base in Kosovo, he saw similarities leaping across the years.

“In Constantine’s time, Roman soldiers were brought in to keep the peace – and now NATO troops were keeping the peace,” says Tom. “And when I went to Camp Bondsteel, it was surrounded by a mound of earth – which is just what the Romans would have done. And if a Roman soldier had been transported to the modern Camp Bondsteel, they would have recognised the place.”

As for the violence that intrudes into most crime novels and thrillers, Tom has no wish to linger on the gruesome details or spin out the nastiness, as some writers do.

“The older I get, the more squeamish I become,” he says.

Instead, he is more interested in writing well-paced thrillers – at which he has had great success, having been translated into some 20 languages.

He is certainly accomplished at what you might call the momentum of menace. Secrets Of The Dead is a proper page-turner. The Roman sections are rich in detail and historical complications, yet the novel wears its learning lightly and whisks the reader along.

Tom, who was chair of the Crime Writers’ Association for 2010-2011, is married to a university lecturer and has two young children. And never mind what it says on the book cover, he definitely lives here in York.