the well, Sadie was showing Martha how to use the walkie-talkie. This red light means it's on. That's the frequency – it's set to channel one. Press this switch when you speak, release it to listen.'
'Gotcha.'
They were looking down into the well, but all they could see was the blue rope disappearing into the darkness. Martha kept thinking she could see the distant glimmer of the Doctor's torch as it moved around the shaft, but she couldn't be sure.
She pressed the switch on the walkie-talkie. 'Doctor? Are you there?' She remembered the way people usually spoke on radio transceivers and added, 'Do you read me, over?'
The walkie-talkie crackled and then the Doctor's voice rang out loud and clear: 'Hello, Martha!'
She laughed with relief and pressed the switch again. 'We can't see you any more. What's it like down there?'
'Dark and cold,' came the reply with a crackle of static. 'There is a lot of vegetation down here, weeds and stuff, but you can tell Sadie the shaft wall is in pretty good condition so far.'
'That's great!'
'Hang on a...' the Doctor's voice faded briefly and then returned, '... to get through here. I'll need... hands to move it.'
'Didn't get that. Can you repeat, over?'
Crackle. 'Lots of weeds and... yes, probably brambles I think. I'll need both hands to move it so I can get past. Hold the rope a minute. I'll have to switch the walkie-talkie off. Over and out.'
The radio crackled and Martha looked at Angela. 'I heard,' she said, and stopped winding the rope out. 'He's doing well, isn't he?'
'I hope so,' Martha said. 'He has a knack of finding trouble, though.'
The Doctor spun slowly in the darkness, watching the light from his torch play over the shaft wall. There was a tangle of weeds and roots growing all over the old brickwork, and a big patch of brambles. The light gleamed briefly on the tips of some viciously sharp thorns.
With great care he pushed aside some of the thinner, more straggling branches, doing his best to avoid the thorns. The brambles grew more thickly below, almost like a barrier.
Craning his neck, the Doctor looked back up the wellshaft. It was very dark, but he could still see a coin-shaped white disc above him. The sky. It seemed alarmingly small and distant. But there was still a lot further to go; he had to carry on.
Steeling himself, he turned back to the matter at hand. He swung himself across the well and grabbed hold of one of the sturdier roots. It was growing out of the shaft wall, but the damage didn't look too bad. Nothing that couldn't be patched up once the vegetation was removed. He twisted around in his harness and shone the torch downwards. He could see a narrow gap through the bramble thicket. If he took it carefully, he could probably climb down right through it.
Beyond the brambles was nothing but impenetrable blackness. The torch beam was simply swallowed whole. He found the walkie-talkie and pressed the call switch. 'Hello up there...'
Martha's voice crackled faintly: 'Hi! Everything OK?'
'I've found a way through the worst of it. You can lower away'
'Right! Lowering away.
The rope hummed and the Doctor positioned himself so that he dropped through the clear way. The odd thorn snagged on his clothes, but otherwise he passed through without a hitch. The brambles closed over his head like a tangled ceiling as he descended into an altogether colder, damper darkness.
The Doctor shivered. It wasn't the cold so much as something else – a deathly atmosphere completely at odds with anything he had experienced on Earth before. It was as if in passing through the brambles he had passed into another world.
The torchlight picked out something else growing up the brickwork; a strange, fibrous growth which stayed close to the walls and was much paler than the vegetation he'd seen so far. Some of the stems looked oddly withered, meandering in a haphazard fashion with milk-white tendrils creeping between the narrow gaps around the bricks. There were other