As a child in the 1960s, Luke Jennings was fascinated by the rivers and lakes around his Sussex home. Beneath their surfaces, it seemed to him, waited alien and mysterious worlds. With library books as his guide, he applied himself to the task of learning to fish. His progress was slow, and for years he caught nothing. But then a series of teachers presented themselves, including an inspirational young intelligence officer, from whom he learnt stealth, deception and the art of the dry fly. So began an enlightening but often dark-shadowed journey of discovery. It would lead to bright streams and wild country, but would end with his mentor's capture, torture and execution by the IRA.