A smashed lock, a bloodstained jacket, a drifting boat...and a takeover bid. Dr. Hardy accepts a case, which takes him out of his own exact world of scientific evidence and into the speculative world of finance. And yet, even in strange waters, with the aid of a few bright feathers and silk thread he solves the mystery of a disappearing man. Guest stars Peter Barkworth, Jean Marsh, Basil Henson, Eric Dodson, Timothy Bateson and Glyn Owen.