Santo Innis is developing a revolutionary new engine to counter the lethal effects of high-pressure steam. His backer is Richard Vaughan, heir to Frederick Tregarron, owner of Gillyvean estate. Following the tragic deaths of his wife and baby son, Richard immersed himself in work. But his world is turned upside down by the unexpected arrival at Gillyvean of Melanie Tregarron, a talented artist and Frederick's illegitimate youngest daughter. Desperate to prove the viability of his invention, Santo persuades Richard to let him fit one at Gillyvean's brewhouse. But when Bronnen Jewell - worried about her mother's suffering at her father's hands - arrives to brew the harvest beer she's horrified, fearing loss of the income on which she depends. As the lives of these four become entwined, a shocking revelation shatters Bronnen's world; desperate for money Santo makes a choice that costs him everything; Melanie fears she will never be free of her past; and Richard has to face his deepest fear.