By Sian Brewis

Ex-smokers everywhere must have united in sympathy for poor Sir Trevor McDonald.

Like a dieter sent on a day trip to Cadbury World and finding themselves surrounded by Dairy Milk, he spent a day at a Cuban cigar factory staring at rows and rows of lovely cigars – just when he’d finally managed to quit.

“Don’t be afraid,” laughs a worker, waving a huge Havana in his face like a hypnotist dangling a watch chain.

“No, really, I stopped smoking... no...” he protests, before giving in with a quick puff, followed by a huge smile.

The factory looked a great place to work. You can smoke as much as you like, then a nice man reads the newspaper to you. Cover to cover. The afternoon’s entertainment is a book.

He’s just finished the Da Vinci Code and is now ploughing a somewhat specialised furrow with a history of Ancient Egypt.

The opening episode of Secret Caribbean (ITV, 9pm) was an unexpected pleasure: a travel show which didn’t involve some annoying celeb wandering around somewhere exotic going “ooh” and “ahh” .

He’s good company, our Trev: genuinely interested in people and possessed of a dry, almost mischievous sense of humour. Lifestyles of the rich and famous don’t seem to hold as much interest for him.

In Cuba, everyone gets free fags and matches from the Government. But you can’t buy a toaster. His guide, Juan, describes one area as “working class”. But aren’t all Cubans equal? asks Sir Trevor. Juan dodges the question.

In Trinidad he throws himself into carnival season. It’s difficult to reconcile the straitlaced newsreader with the sight of him dancing about in a giant gold skirt.

On Nekker, Richard Branson’s island, the millionaire looked pleased as punch with his “office” – a swinging hammock with views over the achingly beautiful island.

More amazing were the people prepared to hand over £30,000 for one night there. One woman, PJ, had “popped over” for three nights with her friends from New York. Sir Trevor can’t believe it. “It’s worth it,” she insists.

Revelations (C4, 7pm) was a gripping, if ever so slightly creepy, look at Alpha courses, 10 weeks of pitching Christianity over free food and Chardonnay.

Ed, unemployed, was signed up by his brother, who’s a missionary, who said: “Unless you find God, you’re going to Hell.” He was expecting a “high pressure sale” but it seemed more subtle than that.

Student Dave says he’s there because there’s more to life than getting drunk, while jobless Mel thinks there’s “something out there” and likes the “great food”.

Alpha looked more like a cult; its inventor, Nicky Gumbel, had deliberately come up with the idea of having free food and drink served by “pretty Christian women”. But perhaps that’s just the marketing.

Comedy writer Ian looked lost in thought. They thought he’d had a revelation. It turned out he was coming up with a routine about Jesus and Moses playing Top Trumps.