Judy Simons thought to leave her grandchildren a legacy of reminiscences about her Jewish upbringing in 1950s Sheffield. But when her mother died shortly before her hundredth birthday, Judy discovered a treasure chest of papers hidden at the back of the wardrobe. Reading them, she realised she had unearthed a gripping family saga.It transformed her mission and left her wanting to know more. The resulting research took her into immigrant ships from the Pale of Settlement, Manchester sweatshops, Victorian lunatic asylums, and the horrors of the concentration camps. This was the unseen backdrop to her suburban childhood.The Northern Line throws fresh light on a forgotten part of Sheffield history, the early days of its Jewish community and its role as a sanctuary for refugees fleeing from the pogroms in the 1880s and from Nazi persecution in the 1930s.It evokes the gas-lamps of Paradise Square and the Hebrew classes where lads lay in wait each evening to throw stones at “the Jewboys”.  Wr