John Stride (The Wilde Alliance) is David Main - a dynamic, highly capable, occasionally impetuous young solicitor who has built up a successful practice in his native Leeds. Although driven by a thirst for success, Main is a man with a conscience who often represents society's most vulnerable and underprivileged - sometimes to the disapproval of his more reserved and cautious partner, Henry Castleton (John Wentworth). This fourth series begins with Main at the top of his professional world. A successful future - despite hard economic times - seems assured. Somewhere, however, there is a lorry driver drinking just one pint too many...and in one terrible instant, David Main's life is changed forever, and his entire future put at stake.