Northwest Passage to Acock's Green

Northwest Passage to Acock's Green takes Boon out of the hotel and on to the water. Erroll McLaverty, a genial Irish businessman, hires Ken to bring a canal boat back to Birmingham from near London, along the Grand Union Canal. It is the kind of job the advertisement was written for, unusual, harmless and paid.

Ken sees a chance for more than wages. He takes Doreen with him and plans a romantic weekend, a rare moment of private life for a man whose first episodes have been taken up with debts and other people's problems. The canal promises a slow journey and a quiet one.

It is neither for long. Two scruffy men, Appleby and Laing, are following the boat, and they are interested in what it is carrying. Then Ken and Doreen hear strange noises from the cargo hold. Hidden below is Alan Prendergast, an escaped convict, and the purpose of the trip becomes clear. McLaverty has used Ken to smuggle the young man back to his father, Walter.

The episode turns on the rule in the advertisement. Ken will consider anything legal, and he has been tricked into something that is not. He is now an accomplice in an escape without having agreed to it, with pursuers on the towpath and a fugitive in the hold.

Douglas Watkinson, who wrote more episodes than any other outside writer on the series, provides the script, and Laurence Moody directs. T.P. McKenna plays McLaverty, and Larry Lamb plays the convict. The title, a joke at the expense of explorers who went looking for a route through the Arctic, sets the comic scale: this passage runs from the Home Counties to a Birmingham suburb.

The journey format suits the programme. The first series was made partly in the studio, and an episode on a canal boat shows what the location work could give it. A pursuit at walking pace is a comic idea in itself, and the confined boat puts Ken, Doreen and their unwanted passenger in close quarters.

It is a well-shaped story. It starts as a holiday, becomes a moral problem, and keeps the romance and the crime pressing on each other. Its limitation is the one common to the first series: the client's deception is the episode's main surprise, and once it is out, the rest is a matter of getting the boat home.

It also gives Rachel Davies' Doreen more to do than most episodes of the first series. She is not at the hotel's desk this time but beside Ken when the trouble starts, and the weekend that was meant to bring them closer becomes a test of how well they work together. For a series that later changed its supporting women almost every year, it is a useful reminder of how central Doreen was at the beginning.