I WONDER how Dr Gregory House is these days? Is he as grumpy as ever and still solving a seemingly-impossible medical malady each week in US series House? Was Wentworth Miller able to stage a Prison Break and stay a free man? And did anyone find the answer when Lost ended?

I only ask because the Sky’s the limit where some programmes are concerned. House, Prison Break and Lost, as well as 24, all disappeared from terrestrial TV channels into the land known as Sky Television.

And now another much-praised cult show is making the move. Mad Men has been snatched from the BBC for screening on the new Sky Atlantic HD channel. Only Sky subscribers will be able to see the fifth and subsequent series.

Those who’ve faithfully watched the first four series on BBC4 will be left hanging in the air about the future of Don Draper, Margaret Olson and all the others in the Madison Avenue advertising agency.

Unless, of course, they care to subscribe to Sky.

This turns followers of the series into mad, as in angry, men and women with mutterings about being blackmailed into buying a Sky subscription.

Money is, of course, the cause of this disruption to viewing. Sky has a habit of making the producers of a programme an offer they can’t refuse.

BSkyB paid around £20m to take the rights for Lost from Channel 4. The baffling plotline about survivors of the crashed Oceanic Flight 815 made it even more frustrating for regular viewers deprived of further episodes.

Sky One’s bid was big enough to win them the rights to Prison Break from Channel Five, which also lost award-winning medical drama House starring British actor Hugh Laurie after four series.

Five put on a brave face saying they’d taken “this difficult decision for commercial and scheduling reasons”, while pointing out it retained the CSI franchise and NCIS, as well as buying new series The Mentalist.

Not that House disappeared from screens immediately as Five had repeat rights for the first four series, while Hallmark also had re-run rights.

Mad Men isn’t the first series to be lured away from BBC2. That channel previously lost the Kiefer Sutherland thriller series 24 to Sky One.

Sky Atlantic, which launched this week, already has the rights to US cable channel HBO’s entire archive. Entourage, which has been seen on ITV, has swapped to the new channel which is also showing other imports such as the new Tom Selleck police series Blue Bloods.

Now-finished series like The Sopranos, Six Feet Under, ER and The Wire are set for re-runs on the new channel. That’s in addition to the British premieres of Martin Scorsese’s award-winning prohibition drama Boardwalk Empire, starring Steve Buscemi.

Mad Men followers desperate for a fix had better make the most of the re-reuns of the fourth series currently on BBC2 following their BBC4 debut, although its late night slot (11.20pm) won’t suit everyone.

The best hope of plugging the gap left when a show performs a vanishing act is the DVD boxed set. Okay, you’ll have to wait a few months, until the series has run on TV, before it is released for home viewing, but the one-off price will be less than a Sky subscription.

And you’ll be able to organise your own repeat schedule if you want to watch it over and over again.

* Mad Men: Monday to Thursday, BBC2, 11.20pm