Whether Numb3rs is partially responsible for the decline in televisual ingenuity or merely a symptom of it, I'll leave that for others to discuss. To be honest, if you can get over the ridiculousness of the premise, it isn't that bad.

Rob Morrow (Northern Exposure) plays FBI agent Don Eppes, who, in the pilot episode, is tracking a serial rapist who brands his victims. When the psycho's latest attack ends in murder, the pressure is on Eppes to catch him, and quickly. But with seemingly no connection between the victims or locations, his task seems hopeless - that is until his little brother Charlie (David Krumholtz, The Lyon's Den) stumbles across his case files. As Don says, 'Charlie can be a pain in the ass, but he's a world-class mathematician.' The brothers are soon on the trail of the killer using complicated equations to estimate his location. Cue swirling close-ups of numbers, graphs and parabolas that reveal maths is not only fun, but useful too. It may sound far-fetched, but the FBI has apparently used mathematicians with a reasonable degree of success in similar cases - although it does seem a little tenuous on this first showing.

In its favour, the show is darker than you might expect and boasts an impressive cast that includes veteran actor Judd Hirsch (Taxi) as the brothers' father and the always entertaining Peter MacNicol (Ally McBeal). MacNicol's portrayal of eccentric lawyer John Cage was the best thing about Ally McBeal and he steals the show again. As Charlie's former professor and mentor, he delivers the kind of cryptic advice that can be relied upon to crack a case. You can't help but wonder, however, how many crimes can be solved using maths and it may not be too long before this show's number is up.

Over on Discovery, there's the chance to catch a true original in Shark Hunter: Chasing the Great White (today at 9pm). This documentary tells the story of Frank Mundus, considered the greatest shark hunter of all time. Mundus began running commercial shark-fishing trips from Montauk in New York state in the 1950s and quickly found fame on the back of the monstrous razor-toothed leviathans he would regularly haul onto the docks. He was even considered enough of a celebrity to front a commercial for Schaefer beer in the 70s, but his crowning glory was the capture of a mammoth, 1.55-tonne great white that, although snubbed by the record books because of a technicality, remains one of the largest sharks ever caught. It is generally accepted that Mundus was the inspiration for the character of Captain Quint, the cantankerous old sea dog with a personal vendetta against sharks played to memorable effect by Robert Shaw in Steven Spielberg's Jaws, and the image of him as an obsessed and difficult man is borne out by interviews with his contemporaries. Mundus' only complaint about the Quint character is 'they didn't make him ugly enough'.

Now 78, Mundus has become involved with shark conservation and is keen to preserve the creatures that were once his nemesis. Shark Hunter sees him travel to South Africa to get a close look at the astonishing 'flying sharks' that inhabit the waters south of Cape Town. These great whites leap out of the water when hunting seals, offering one of the most spectacular sights in nature. Mundus

also meets Andre Hartman (above), a shark expert who has clocked up more than 1,000 free dives (without cage protection) with the creatures and whose idea of fun is to grab the killers by the nose and give them a playful push. Finally, don't miss the thrilling conclusion of series one of Desperate Housewives (TVB Pearl, Thursday at 10.35pm). There are more unseemly secrets hidden behind the polite facades of Wisteria Lane than there are in an American president's past, and this season finale reveals a satisfying array of them, not least of which being what really happened to Paul Young's (Mark Moses) missing daughter.

This show has quickly filled the vacuum left by the departure of Sex and the City (in fact it could easily have been titled Sex in the Suburbs), but the added whodunnit edge makes for strangely compulsive viewing and ensures it stands out in its own right. That said, presumably Frantic Newlyweds and Drastic Grandmothers are already in production.