On Sunday 12 September 1999 Mrs Norwood, an 87-year-old widow and great-grandmother, an atomic spy whose luck had held out, explained to the world's media over her garden gate why she had spied for the Soviet Union from 1934 to 1973. Outed the day before in The Times as the longest-serving female Soviet agent in the West, and charged with passing to her Soviet controller Britain's atomic bomb secrets, she remained defiant. Over her right shoulder in the window of her living room could be glimpsed a poster demanding ‘Stop Trident’. A lifelong member of CND she had made her contribution to nuclear weapons proliferation by shortening the Soviet atomic bomb project by several years.

Mrs Norwood was born Melita, or Letty as her father fondly called her, Sirnis on 25 March 1912 at 402 Christchurch Road, Pokesdown, in East Bournemouth. Her father Alexander Sirnis was a revolutionary socialist, a member of the London branch of the Social-Democracy of Lettland, a militant organization affiliated to Lenin's Russian Social-Democratic Labour Party (Bolsheviks). He was also a member of the British Socialist Party, a Marxist body affiliated to the Labour Party, calling for the revolutionary overthrow of British capitalism. Letty's mother, Gertrude, who came from a well-to-do family of doctors and solicitors, was a suffragette and a supporter of the Labour Party; her views were thus no less progressive than her husband’s. Letty shared many of the characteristics of her grandmother, Elizabeth Gurney Stedman (1851–1943), who possessed a literary and philosophical mind, and when quite a young woman had written a little book entitled No Humbug. According to her friends and acquaintances there was a strong vein of self-reliance in her character, and she needed no assistance in dealing with difficult situations. ‘She used to claim she was “afraid of nothing on earth”, but she had a horror of big spiders! Her memory was good.’

Melita Norwood had been brought up in a family environment that, while not austere, was certainly hard working. On her mother's side the family ancestry was solid Sussex yeoman stock. The Stedman family had been landowners in Itchingfield, near Horsham, West Sussex, for over 600 years. An entry in Sussex Genealogies on Stedman of Itchingfield notes that the surname Stedman occurs with reference to Itchingfield as early as the year 1324 ‘when Simon Stedeman owned a messauge and half a virgate of land in Horsham and Hechyngefelde’.