AUTHOR Katharine McMahon got the perfect career boost last year when her novel The Rose of Sebastopol was included in the Richard and Judy Book Club choice. Like the other Richard and Judy selections, it flew off the bookshelves and raised the profile of

AUTHOR Katharine McMahon got the perfect career boost last year when her novel The Rose of Sebastopol was included in the Richard and Judy Book Club choice.

Like the other Richard and Judy selections, it flew off the bookshelves and raised the profile of the author.

Now Katharine - whom St Albans audiences know as the Company of Ten actress Kate Rainsford - is back with her latest novel, The Crimson Rooms, which promises to be every bit as successful.

It is the story of a young lawyer, Evelyn, who is haunted by the loss of her brother James in World War One.

Her life changes when a young woman appears on the doorstep of her London home late one night bringing with her James's child and she becomes involved in two unusual cases which pit her against social injustice of the time.

Katharine is a magistrate herself and she believes that gave her the confidence to write The Crimson Rooms which, like all her other novels, is meticulously researched.

She explained: "I was interested in the fact that a woman could not be a lawyer until 1920 and I felt safe writing about someone working in courtrooms."

She was particularly fascinated by three areas of research, one of which was the dark subject of the immigration of children overseas in the 1920s. She said: "I did a lot of research in family law and the whole business of children in care and then got into the history of Barnardo's.

"It was felt to be better for the children to go overseas but they didn't know what they were going to."

She also became particularly interested in the impact of shellshock on survivors of the war and the violent crimes which were committed when it was over - a subject tackled in The Crimson Rooms by the trial of Stephen Wheeler who is charged with the post-war murder of his wife.

The novel also gave her another opportunity to delve into the role of women in a particular era - something she has examined in both The Rose of Sebastopol and its predecessor, The Alchemist's Daughter, although both were set in different periods.

But there was one outcome which emerged as paramount. "What became absolutely clear was that the whole thing was connected to the war and Evelyn's feelings about her brother."

In Evelyn, Katharine has come up with a heroine who bears another outing but it is not something she has done before and she is reticent about taking such a step for the time being at least.

In fact her next novel is set in the French Revolution but true to form, it is taking an English angle and has led to all kinds of interesting research about the role of women at that time.

Katharine is more than grateful for her Richard and Judy nomination but she is quite clear why she writes and what the end result has to be. "In terms of my career it was superb and boosted sales but the be-all and end-all is that people enjoy my writing."

The Crimson Rooms is published in hardback by Weidenfeld and Nicolson and retails at �18.99.