It's The Monkey's Paw of Quantum Uncertainty -- Unintended Consequences.
[Cave]
HORG: They are coming.
(The stretcher is put down and the travellers dragged away)
Cain :
Za and the woman went
with them. I, Kal, stop them.
HUR:
They saved Za from death near the stream.
Cain :
They set them free from
The Cave of Skulls and
went with them.
HUR:
The old woman cut them free.
Cain :
Za is so weak a woman speaks for him.
HUR:
It was the old woman.
She showed them a new way
out of the Cave of Skulls.
Cain : The old woman does not speak.
She does not say she did this or did that.
The old woman is dead.
Zakilled the old woman.
HUR:
No!
Cain :
Za killed the old woman
with his knife.
HUR:
No.
Cain :
Here. Here is the knife
he killed her with.
Old Grandfather :
This knife has no blood on it.
I said, 'This knife has no blood on it.'
Cain :
It is a bad knife. It does not
showthe things it does.
Old Grandfather :
It is a finer knife than yours.
Cain :
I, Kal, say it is a bad knife.
Old Grandfather :
This knife can cut and stab. I have
never seen a better knife.
Cain :
I will show you one.
(Kal pulls out his flint knife)
Old Grandfather :
This knife shows what it has done.
There is blood on it. (to Za)
Who killed the old woman?
Abel :
I did not kill her.
Old Grandfather : (to Kal)
You killed the old woman.
Cain :
Yes! She set them free.
She set them free.
She did this.
I, Kal, killed her.
Old Grandfather :
Is this your strong leader? One who
kills your old women?
He is a bad leader. He will
kill you all. Yes, all. (to Ian)
Follow my example.
(The Doctor picks up some stones
and throws them at Kal)
Old Grandfather :
Drive him out. Out.
Friend:
Yes, drive him out.
He killedthe old woman.
(The Tribe start pelting Cain with stones)
The Tribe of Gum :
Drive him out.
(Kal leaves, and Za is
on his feet again)
Friend :
Remember --
Kal is not stronger
than the whole tribe.
Abel :
Kal is no longer
One of This Tribe.
We will watch for him.
We will all fight Kal
if he comes back.
We will watch for him.
Take them to The Cave of Skulls.
Friend :
Take us back to The Desert and
we will make Fire for you.
Abel :
The great stone will close one place, and you will
stand by another I will show you. Take them.
Old Grandfather :
Don't struggle.
Abel :
They are inside the cave.
You see them come out, kill them.
Regeneration is a roll of The Dice, it's A Game of Chance -- throughout all the scenes with The Toymaker, there are always many, many embedded games; elsewhere, The Toymaker offered the following explanation as to WHY he is so fixated on Games, when he is Functionally Immortal, and older than the (current) known universe, with the reality-warping powers of A God (within the focus of his immediate concentration of attention, only) :
" Meaningless destruction is as appetising as meaningless creation and just as unfulfilling...
Until I found distraction in The World of Games, until I could throw off the pretence of Purpose and Meaning, until I too could be a prey to Chance and Hazard ..." -- that's why he makes himself subject to the arbitrary rules of whichever game he has challenged his opponents to play.
As The Doctor points out, to cheat at any of these games is the one thing that He will never do, but the second half of that sentence is that before he makes any challenge, he will have already set The Rules in his favour every time -- and because he won't tell you what they are (until you break any of them), and he won't even tell you what kind of game it is that you both are actually playing, even, he gets off on people blundering headlong into their own destruction, based off false assumption -- which means that in order for him not to win every time, The Universe has to get creative in thwarting him in his (unfair) intention to trap you -- Much like Ruby's Snowstorms and the VHS White Noise, it's the unforeseen randomness and chaos that he didn't expect, didn't think of and didn't account for when he set the conditions for The Test and made the challenge to his opponent, whilst trying to Control The Games....
The Toymaker looked on, though with a faint smile creasing his mouth now, as he saw the two extra Lives vanish, snuffed out like tiny candles. And his eyes glinted.
The counter moved again, not spinning frantically now, but turning through treacle, past 125,000 and towards The Toymaker’s High Score. Stefan looked on aghast. Not a muscle moved on The Toymaker’s face.
The streets were littered now with broken monsters, cracks starting to appear in the asphalt where the firefight had proved too much for the substance to stay stable. The cracks widened as the very ground rumbled. The frantic pitch of battle had slowed also, the steady crunchcrunchcrunch now returning to dominate the scene. The Doctor, exhausted, looked around for the source of the noise. There was something... something his other brain was telling him, something washed in or washed out by the fighting, by the insight he had into the mind that devised The Game.
The Score hardly mattered.
He knew he had only one life left and he had to find The Answer before that was gone. Had to stay alive and find The Answer... had to fight on... had to fight on...
The street filled with screaming crushing monsters one after the other as he blazed away, using the weaponry he had left as a hosepipe more than a precision piece. One life left and he was called back, called by the blare of electronic trumpets as the High Score was swept away. One more, two more, three bursts and again the street was clear before him...
One life left. Still one life...
One that was The Answer...
One... One alone...
He turned from The Machine, sweat pouring from him, scars that would never show criss-crossing his mind. ‘You’re alone,’ he croaked hoarsely at The Toymaker. ‘One. One alone.
There’s just you, no one like you. Ever.
This Game – an empty city, a ghost city. And one, just one fighter, one enemy, one on his own...
You’re not from this Universe, are you?’
He turned and walked towards The Toymaker, past the speechless Stefan, who had just witnessed, for the first time in eight hundred years another being’s victory over his Lord and at one of his Lord’s own games!
‘The Game,’ stammered The Mandarin, ‘you’re not thinking about The Game!’ There was a blare from The Machine as The Doctor’s last life was lost. The counter had come to a stop. 131,000, and The Toymaker’s score was languishing under ‘Last Player’.
The Doctor appeared not to notice. ‘You’re not from this Universe,’ he repeated, ‘that’s why there’s no trace. That’s why The Laws of this Universe don’t concern you. You’re from another Time and Space!’
The Doctor was in full flow as the ramifications of his theory crashed in on him. Behind him, the game machine’s ominous crunchcrunchcrunch had started distantly in the background. No one took any notice of it. Not yet...
‘Whatever catastrophe it was,’ The Doctor continued, as much to himself as to anyone else, ‘it hurled you from your own universe into this one. You carry your own matter with you – you’d have to – not anti-matter, of course, otherwise you’d have started the next Big Bang – but different from ours.’
He paused, thunderstruck by his own conclusions. ‘Relativity,’ he breathed, ‘follow it through...’
He swung round on The Toymaker again, ‘Your own universe is receding from this one so fast, it’s pushing your time back as it goes!’ He stared at The Toymaker, awestuck. ‘You’ll live for millions of years!’
The Toymaker had a look of crushing despair on his face as he croaked out, ‘I have done...’The crunchcrunchcrunch was getting louder. A figure had appeared at the centre of the screen, and was growing larger, growing closer...
‘The isolation of aeons,’ whispered The Doctor, overcome with compassion for the being he’d detested all his adult life. ‘The crushing loneliness of thousands of millenia... you poor, poor creature...’
The Toymaker’s eye was cast on a far, far distant horizon, lost in a world vanished aeons ago. ‘... and then I grew tired of even creating... ships, cities, continents, whole planets even.
I created Life.
I colonised, I helped it survive and thrive for millenia, hundreds of millenia, thousands...’ His voice trailed off as he remembered, as the bitterness and the loneliness overcame him.
He rounded on The Doctor, his eyes turning away from the softness of remembrance to the fury of the present. ‘Until I came to destroy, wantonly, wilfully, the same ships, the same planets I’d helped to create, and that too became too easy and too empty...
Meaningless Destruction is as appetising as meaningless Creation and just as unfulfilling...
Until I found distraction in The World of Games, until I could throw off the pretence of Purpose and Meaning, until I toocould be a prey to Chance and Hazard...’
The glint was back in his eye now, more dangerous than ever before as it merged with the gleam of triumph. The Doctor, seeing the difference, whirled round to see the formation of The Monster on The Screen, to see it grow larger and larger until The Screen could not contain it. The crunchcrunchcrunch had reached its inevitablecrescendo, and The Electronic Monster stood outsideThe Machine, brighter, if anything, and more terrible than before.
The Toymaker’s triumph screeched out at last. ‘A Hazard, Doctor, which you have lost!’
The monster turned and lumbered slowly towards the transfixed Time Lord.