It’s become a common thread in recent Doctor Who episodes to emphasise the extent to which the appearance of a time-travelling eccentric in an inter-dimensional phone box tends to play havoc with a human’s sense of self. Davros taunts the Doctor about this in Journey’s End, mocking him for turning ordinary people into killers, while affecting a morality about holding a gun.

But if you were to sit with the Doctor, and go through the effect his arrival had on all of his companions, Mickey Smith is the one he should feel no guilt about whatsoever. OK, he stole the man’s girlfriend, but if we can take anything away from Mickey’s experience meeting his parallel world doppelganger Ricky Smith, it’s that the soldier was always within him, waiting to come out.

There’s a lovely parallel between Mickey’s first dealings with the Doctor and those of the actor Noel Clarke. Having not been a major Who fan before the series started, and also not being aware of the note of serious drama the relaunched show would aim to strike. Noel has since admitted that he didn’t really get his head around the character before starting work.

This is all to the good, as his job at that point was to portray the person left behind by a companion – his girlfriend Rose Tyler – in bewildering circumstances, and under a barrage of withering scorn from the Doctor, who took to calling him “Mickey the idiot.” If Noel felt overawed by the production as an actor, that’s nothing compared to Mickey’s reaction to the discovery that aliens are real, and that one of them has run off with his girl. Oh, and while she’s missing, he’s the prime suspect in her disappearance.

Here’s Mickey, playing the fool:

http://www.youtube.com/watch?v=7oyHj71twxo

Luckily, by the time Rose and the Doctor return, Mickey and Noel have got their heads around the job in hand. In fact, Mickey turns out to be a whizz at computer hacking, helps to defeat the Slitheen and even refuses the chance to travel in the TARDIS. He relents on this eventually, but only after he’s again proven his worth, and had a minor crisis of confidence, comparing himself unfavorably to K9: “Oh my God! I’m the tin dog!”

It’s not until the trip to the parallel world, where the Cybermen are being built, that Mickey realises his true potential. Ricky Smith, the parallel Mickey, is everything Mickey is not. Assured, driven, confident and a natural leader. Once Mickey realises he is that person too, he becomes the soldier we see as the Tenth Doctor says goodbye, fighting alongside his wife, Martha Jones.

But Mickey’s transformation comes only because he got to take a long hard look in a mirror, a mirror with attitude, one which looked him up and down, just as the Doctor did, and found him wanting. Other companions change because they feel inadequate next to the Doctor, but Mickey was inadequate next to himself. And when Ricky dies, that’s all the spur he needs to step up and sort himself out:

So while it’s the Doctor’s involvement that causes the change, it’s one that was waiting to happen all along.

Next: Captain Jack, the Doctor’s oldest companion by billions of years.

