Tony Williamson

5 November 1969 (IMDb) or 13 January 1970.

2^nd February, London in England

A couple pull over to have a snog. The man has his tongue in the woman’s mouth (maybe) when she draws back and cries "Look!" They see a figure stumbling around at the other end of the street.

It is a space man. He seems in some distress.

The woman screams. The space man collapses. They go over and gingerly stare at the body. A stout British bobby turns up to join them. An actual space man lies dead at their feet.

Who is he? Which planet does he come from? Why is he in London, England?

Scour the globe – we need Department S to drop everything and come to explain.

The astronaut isn’t known to NASA or the Russians but forensics confirmed he’d been exposed to sub zero temperatures, a vacuum and was slightly radioactive.

The astronaut has form – he’s done stretches in the big house and has only just been released. Not the first man you'd choose for a mission to the stars.

Four and a half minutes into the episode, he’s feeding mice in a laboratory. Rather sweetly they are called Jason, Annabelle and Stewart. They’re probably about to have shampoo put in their eyes and gas squirted into their lungs so he ought not get too attached to them. Interestingly, he seems fairly unimpressed with the idea of animal testing.

Lots of famous or familiar actors in this one -

Duncan "Galloway" Lamont, Sally-Jane Spencer (Linda in 'Reggie Perrin'), Stanley Lebor (Howard in 'Ever Decreasing Circles'), Tony "Glitz" Selby, John Nettleton (Sir Arnold in 'Yes (Prime) Minster') and the lovely Wanda Ventham.

She is left to sit at Stewart’s bedside because she’s better at it. I don’t know if that’s meant to mean she’s got more experience of Stewart in bed or that she’s a woman and therefore has caring instincts a man could only dream of.

She gets smacked in the face by Tony Selby at one point. The baddies want to finish her off but some quick thinking by Jason saves her. The experience causes her previously voluminous Tara King hairdo to collapse.

She punches data into their computer ("Auntie") using this slim line interface.

The forensic scientist seems to be having a facial hair competition with Jason. If he’d invested in a bottle of "Just for Men" he might’ve been in with the chance of an honourable draw.

Jason has a date at a club called "The Shake and Shout". We see a montage of people shaking and shouting. Including this one who, unless you look closely, appears to have a moustache.

It literally isn’t possible to tell whether Jason is under cover in this scene or just relaxing.

One of the people round this table doesn’t quite fit.

Jason decides to go undercover on the spur of the moment. He has the man he’s impersonating's passport and thinks he’ll pass if he tells them the photograph was taken before he grew his moustache. He doesn’t say anything about the teak finish.

This of course means Jason gets to use his American accent.

He doesn’t look awfully butch when wearing the space suit.

I don’t want to turn this into a "Doesn’t Jason King Look Silly" piece but doesn’t Jason King look silly?

At the Shake and Shout the legs go on all night.

Stewart meets Sir Curtis for his traditional briefing. Aside from a brown overcoat, Stewart seems a festival of dark blue.

He goes to visit John Nettleton and is thoroughly rebuffed. He suggests the company has lost a space suit, Nettleton says they haven’t, Stewart says he can check the serial numbers, Nettleton says their system is simpler – they just look at the rack and count.

A man with a very red face resents Stewart’s interference and adds a gas canister to the otherwise excellent air conditioning in his car.

The gas has a very strange effect. First it makes him smile.

Then laugh like a drain.

And finally give into mirth all together and drive off into the undergrowth.

The gas which did all this? Why, pure liquid oxygen. Stewart was as drunk as an owl. So high he could’ve floated out of there (which he didn’t – he fell and rolled a bit).

He gets out of hospital and is back in a brown suit immediately. No one ever got high as a kite in a brown suit (there is an Angus Deaton joke in there somewhere). Annabelle meanwhile has come to work in the world’s worst dressing gown.

The scene gets far browner when the latest suspect turns up. Even the wallpaper and curtains are joining in.

He has a stroke of genius later – Annabelle has had no luck tracing likely targets for a raid so he suggests simply listing all locations in London which could possibly require a space suit. Bingo.

Jason thinks that pure oxygen sounds like a marvellous way for someone to try and stop Mark Caine. He makes a mental note.

Jason puts Leila up at "a friend’s" apartment. She finds lots of Jason King novels there including this one – "The Lady Is Willing" – which leads to some saucy banter.

He later tells her "If you can’t sleep there is a collection of my novels in the bedside table" which I’m assuming wasn’t deliberately self-depreciating humour from Mr King.

Jason suggests the space suits were stolen for a "fast getaway upwards". Annabelle rolls her eyes and he tells her she should read his books. Which suggests Mark Caine fought crime in space long before Roger Moore.

Now this is what Department S was made to do - a man in a space suit wandering the streets of London? Fantastic. Jason King in a night club, someone tries to kill Stewart in an unusual way and Annabelle crunches numbers in a computer the size of a tennis court. And top it all off with an explanation which makes perfect sense. Department S - and ITC in general - don't get much better than this.