Oh Mr Porter! What a silly show I am

Horizon: How To Commit The Perfect Murder, BBC2

JESSIE Wallace - Kat Slater, innit - played Miss Marie Lloyd but she wasn't the star of the show for me. No, the mysterious bloke billed only as "The Showman" (played by Shaun Parkes, from the Inspector Lynley series and last year's Satan Pit episodes of Doctor Who) stole this ridiculous biopic of the music hall singer. Everywhere Miss Lloyd went, from her early days as hopeful ingnue to becoming the biggest-earning star there had ever been, there he was, lurking around in the background of scenes making knowing faces.

He was there when her doughy charms captivated Guy of Gisbourne (Richard Armitage, a good actor who these days is sadly struggling in terrible roles) and won her a job in the chorus line. By dint of camping it up with a hat under her dress to simulate pregnancy, she was soon flashing her ankles and singing saucy songs to become the hit of Edwardian London. "They love me!" she trilled, just before marrying Sir Guy, alias stockbroker Percy, but the Showman was there to nod meaningfully at the camera to tell us that All Is Not Well.

Without any kind of explanation, suddenly Percy was running up debts, shoving her around, carousing with ladies who showed even more than their ankles and generally behaving like a cad. Meanwhile, people were always asking for Marie's autograph, even the bailiff who turned up to collect Percy's debts. "I don't give a raspberry tart!" she yelled, to the shock of a douce lady in a tearoom, who promptly launched a campaign to close down the music halls due to her act's vulgarity - to which Marie responded by dressing as Britannia and flashing Union Flag knickers.

There were some unintentionally priceless moments in this awful script, which made a pig's ear of what was obviously an interesting life. I liked her second husband, gormless Pearly King Alec, responding to her attempts to seduce him over breakfast in bed with the gruff injunction: "Eat yer egg." And the close-ups of newspaper cuttings became very funny when you could clearly see that the stories beneath bore no relation to the headlines above.

But for true hilarity, the constant popping up of Parkes, whether singing a song or just rolling his eyes at the camera, was the highlight. At one point, he was lurking significantly at her dressing room door when she got up, and I honestly thought she was about to yell: "Look, 'oo the 'ell are ya and why are you always hangin' around? Leave it aht, mate!"

Was he meant to be invisible, a Jiminy Cricket conscience or a Che-in-Evita style manifestation of the chorus? And what was the purpose of Marie's fey friend who seemed to have nothing else to do in life but mooch around looking like Jude Law? I have about as much idea as I have of why this mad tosh got past the script editors.

Wallace was perfectly fine in the role, giving it as much of the old Slater oomph as she could, but she'll have to find much better things than this if she wants to escape typecasting.

Horizon's rather sinister film was hard to watch for different reasons - and much less funny. Apparently you really could kill someone with a frozen-ice pole, thus dissolving the weapon, while biological washing powder at 60C will melt meat from bones. But, in case this seemed too much like a useful manual for criminals, it was pointed out that something always goes wrong. Well, obviously - we only know about the ones who get caught.