Even on that slack definition, Butterfly Collectors barely qualifies since, whatever else you say about it, it isn't noticeably tense. Investigating the murder of a small-time drugs dealer, DI McKeown (Postlethwaite) develops what amounts to a crush on a suspect, Dex (Jamie Draven) when he discovers that, with his father dead and his mother absconded, the 17-year-old is fending for his younger brother and sister. Dex seems to have the maturity, self-assurance and domestic contentment that McKeown longs for. Within about half an hour he's paying for Dex's lawyer, employing him to tile his kitchen and organising his birthday party. But then suspicion rears its ugly head: what really happened to the parents? Is Dex just a keen gardener, or is there some other explanation for all that freshly-dug earth in his back yard?
If I had to pick the real culprit, I'd plump for Dex's delinquent younger brother, who has already shown himself disturbingly handy with a baseball bat. But I can't say I feel very concerned about it. McKeown and Dex's friendship may develop at an improbably swift pace, but otherwise Paul Abbott's script just creeps along, enervated by a soppy score - Erik Satie meets Clannad. Meanwhile, Postlethwaite's nobbly features have been twisted into a rictus of anxious passivity that makes it hard to work up any concern on his behalf. Even if it turns out that Dex is a murderer, the worst that can happen to McKeown is that he loses a job he doesn't like.
Elsewhere, we had an unofficial Shoddy Engineering Night. Equinox (C4) looked at the wobbly state of the leaning tower of Pisa, now being rescued, after centuries of mismanagement, by British engineering ingenuity. Disaster (BBC2) put that concept into perspective, recreating the Windscale fire of 1957, the world's first major nuclear accident and a product of lousy British design. Because the core of the Windscale reactor was air-cooled, when a fire started, shutting off the air supply - the most effective way of putting out a conflagration - allowed the reactor to heat up to such a degree that it was in danger of exploding. This was a scandalous tale of incompetence and government cover-up. The level of radioactive contamination of the surrounding countryside was not revealed for decades. Even damped down by stilted acting and timid special effects, this semi- dramatised film was still more gripping than most psychological thrillers.Reuse content