I went on a family holiday to Wales and the house we rented had a home cinema so we spent three nights watching Torchwood, Children of Earth on DVD. There were nine of us watching, male and female ranging in age from 14 to 51, and the unanimous verdict was – brilliant. In fact, there were even suggestions that we stay up all night and watch the whole thing (we didn’t!).

To give some background, the Torchwood series is a spin-off of the popular children’s sci-fi show Dr Who. The name refers to a supposed secret British organisation set up by Queen Victoria around the middle of the 19th century to defend the country against aliens (the extraterrestrial kind). This organisation was mentioned when Dr Who (as a time traveller) met Queen Victoria in the episode called Tooth And Claw.

Torchwood stars John Barrowman as Captain Jack Harkness, also a character from Dr Who, who has a superhuman quality – he cannot age or die! The mini-series Children of Earth was shown over five nights on BBC1. It’s set in the Welsh capital Cardiff where Torchwood operative Gwen Cooper (Eve Myles) notices a child has just stopped in the street and is completely unresponsive to his mother’s pleadings. It seems the children all over the world are acting in the same way – they seem to zone in and out of consciousness. Day by day, the children start to act in more and more bizarre ways, intoning in unison ‘We are coming’. Captain Jack and colleague Ianto Jones (Gareth David-Lloyd) are on the case at once - but so is the government.

When it transpires aliens are controlling the children and Captain Jack has had dealings with these aliens 35 years earlier, the government think Torchwood is against them and the fight is on.

The action moves to London with a weak and vain prime minister and a civil servant John Frobisher (played brilliantly by Peter Capaldi) who prides himself on doing his job – no matter how immoral the orders. One excellent line describes civil servants as ‘the cockroaches of government’ – they survive when minsters are voted out. It is Frobisher, who has children of his own, who is selected to speak to the aliens.

When we discover that the 456 (as the aliens are called) want to have a tenth of the world’s children, there is a chilling and depressing discussion in cabinet with the prime minister and other ministers about how the children are to be selected. No one round that table wants their own children to be sacrificed so they decide it must be those from the worst performing schools – ‘If we can’t identify the worst schools, then what are the League Tables for?’ says one government minister.

The great thing about Torchwood (and Dr Who) is that it appeals to young and old, male and female. This script, written by Dr Who stalwart Russell T Davies, is excellent, the acting is thoroughly convincing. One tiny pedantic comment – the children affected are supposed to be under the age of 11 yet Frobisher’s elder daughter is clearly older than that.

However, I remain unconvinced about the ending. I won’t describe it so as not to spoil it but let’s start a discussion on the forum.