I only slept soundly in my bed as a little girl because I knew the daleks couldn’t get up the stairs. Friends of mine tell me they cowered behind the sofa on Saturday evenings, as they heard that dreaded mechanical voice ‘Exterminate!’ Daleks, with their faceless metal bodies, harnessed every child's terror of untamed danger, and Steven Moffat, the Doctor Who writer – and now also Executive Producer – makes ample use of faceless monsters in his scripts for this iconic British sci-fi drama.

Two earlier episodes that epitomise his genius are ‘The Empty Child’ and ‘Blink’. The ‘child’ in the first drama wears a gas mask – a terrifying image that taps in to our fear of the unknown – while the plaintive child voices our worst primeval fear of abandonment ‘are you my mummy?’ The very first episode of Doctor Who ever screened in 1963 was called 'An Unearthly Child' and Moffat plays tribute to this. Spooky children are always good horror fodder.

Because the Doctor travels through time and space, he is also a lost soul and the 11th Doctor, played by Matt Smith, is brilliant at bringing out our sense of fun, but also of compassion. He’s such a quirky genius, that much like Sherlock Holmes – and Moffat also writes the new BBC adaptation ‘Sherlock’ starring Benedict Cumberbatch – we are in awe of him at the same time as feeling slightly sorry for him. Somehow he doesn’t quite ‘get’ it, socially and even if saving the Universe is all part of the day job, he is also vulnerable, like a lost child.

In ‘The Outer Limits’ that other fabulous, iconic sci-fi/horror series from way back when, I once watched an episode about a lost soul crying by a crypt in a graveyard, ‘Mother, Mother let me in!’ It was terrifying – and I saw it with eyes closed, or through parted fingers. I wonder if Steven Moffat ever saw this episode, as it is so redolent of the Empty Child, and once again expresses the universal fear of our inner child, alone and missing our mummy.

In ‘Blink’ Moffat even takes away our last refuge from fear - every person’s ability to hide from terror by closing their eyes, or looking the other way. The beautiful sculpted stone angels are deadly. As well as reminding us of the statues in cemeteries, they live off the energy we have yet to use up by banishing us back in time, unless we fix our eyes firmly upon them.

This is the scary nature of time travel – we all want to be who we are now, and even if nostalgia may seem attractive no-one really wants to be banished. And this is the central paradox of Doctor Who – who is he, and how long will he be who he presently is? As the Time Lord has already regenerated 10 times he must have a sound sense of ‘self’ not to be a gibbering head case, as he stares at his own demise persistently through time.

There is a theory (OK – it’s mine!) that you most love the Doctor you first knew, and for me it was the original Doctor, played by the old English gent, William Hartnell. This show is ageless – there will always be another Doctor – and yet you become so emotionally attached to the current Doctor even with the knowledge that he must be replaced. No one believed that David Tennant could have a worthy successor – wonderful as he was – and yet Matt Smith is just adorable, whacky yet really clever and a real sweetie - as his maybe ‘missus’ River Song likes to call him.

So then – to the latest two part episode, the first part of which went out on TV on Easter Saturday, 2011. Well it didn’t quite ruin my Easter Sunday to realize the final part was not to be screened that day. ‘The Impossible Astronaut’ starts off with all the usual Moffat plot devices – hidden faces (space helmets), a need to keep your eyes fixed on the monsters (lest you forget they are there), and fear of loss. And as this drama opens with the biggest fear of all – and I won’t spoil it for those who haven’t yet seen it – it seems intolerable to have to wait a week to see the next part.

It has a brilliant sense of time – the plot deals with death and resurrection, just like Easter! – and it was broadcast just over a week since the 50th anniversary of the first space man to circumnavigate the globe. Along the way the Doctor storms the White House and is just generally great. There is a particularly intense bit where this archetypal English boffin comes face to face with a US astronaut fresh from the 1969 moon landing, and complete with the stars and stripes on his space suit sleeve. As one of the characters says of River Song at the start of the show – ‘She’s gone to a planet called America!’ And fabulous it is too.

Once again Doctor Who deals with life and death, love and fear, spectacularly. Mysteries of the Universe are effortlessly revealed – though mind you, I still don’t know the answer to this question. What exactly is wrong with Thursday afternoons? You’ll have to ask the Doctor for the answer to that.

Doctor Who: The Complete Fifth Series [DVD] US

Doctor Who: The Complete Specials (The Next Doctor / Planet of the Dead / The Waters of Mars / The End of Time Parts 1 and 2)

Eileen O'Sullivan highly recommends these DVDs available on Amazon US - and she saw the original episodes on British television