TAFF VALE: In 1900 the railway workers of Taff Vale embarked on a strike which has political implications to this day. Timewatch examines the first great clash between the Trades Unions and the law. THE ISLAND AND ITS PAST: How the people of the Isle of Dogs in the Thames Estuary are rediscovering their past. SPECIAL BRANCH: At the height of her powers, Victorian Britain boasted that she didn't need a political police. After explosions in the Underground, the Tower of London and the Houses of Parliament, she changed her mind. Timewatch investigates the birth of the Special Branch.