'I'm going to live in that house, Dad. One day I'll be mistress of Thornsby Manor . . .'

It is 1910 in the Lincolnshire Wolds. Fourteen-year-old Rosie Waterhouse lives with her father, Sam, well-known as the local poacher, in a cottage on the Thornsby Estate. The land is owned by William Ramsey, a harsh and heartless man, determined his only son, Byron, should marry well and produce an heir.

Rosie is quick to learn the tricks of her father's trade and it's when she's poaching fish from the estate's stream that she meets Byron. They continue to meet in secret over the coming months and as their friendship blossoms, they recognise, despite their vastly different backgrounds, that they are destined to be together. When William learns of their friendship, he stops at nothing to ensure that they never meet again.

As the years pass and the threat of war becomes a reality. Sam is involved in a tragic incident which will affect both his and Rosie's lives more than they could ever imagine. Life will never be the same in Thornsby, but will Rosie find the happiness she yearns for?