Esteemed astronomer Alex Christie, the eldest and most steadfast of the Christie siblings, has never possessed his late father's ruthless business drive. But to protect his frail infant son from his cruel father-in-law's bid for custody, the young widower must undertake Sir William Christie's posthumous million-dollar challenge: to make a Glasgow cotton mill profitable. At sea in an industrial world of sabotage and union agitation, Alex meets Polly Gowan, daughter of a famed union leader, who hopes to seize a mysterious saboteur without involving the police. Because a sympathetic mill master would aid her cause, Polly becomes Alex's guide to urban Scotland ...