When Tony Williams finds himself made redundant from the office of Customs and Excise in Southampton, his world falls apart... One morning, his self-esteem at a very low ebb, he receives a letter from Roger, an old friend of his boyhood days, inviting him to join him in his yacht with the idea that they should cruise the local waters; including the Solent. In spite of Tony's reservations concerning sailing boats, he decides to give it a go. It soon becomes apparent that Roger has another reason for inviting his friend. He suspects that he has chanced upon a smuggling operation. With Tony's help, he is inclined to investigate. However, although they succeed at night in witnessing the rendezvous of the suspect contraband yachts at Old Harry Rock, which are detached lumps of cliff marking the entrance to Poole Harbour, they are left with a mystery. Unfortunately the gang get wind of their investigations, which almost leads to a disaster at sea. They suspect that the customs office in Poole had blown their cover. The question is who was responsible? Tony contacts the investigative branch of Customs and Excise, which results in a short term commission. He relies on Roger's intimate knowledge of the creeks and harbours of the Solent waters. Just as they think that their contribution is no longer required and they can complete their cruising plans, they unwittingly find themselves in a potentially catastrophic situation. When the final plot is revealed, they are in for a few surprises.