‘Ah yes,’ said Clara. ‘The Great Work. And what exactly would that be?’

Mrs Gillyflower’s eyes flashed like garnets. ‘That would be telling, wouldn’t it?’

The Doctor, who was not backward in coming forwards, grinned good-naturedly. ‘I’m the Doctor, you’re nuts, and I’m going to stop you.’

Mrs Gillyflower shook her head sadly, as though taking pity on him. ‘I’m afraid,’ she said, pressing a wrinkled hand to her capacious bosom, ‘Mr Sweet and I cannot allow that.’

‘Oh yes. Mr Sweet.’

‘When do we get to meet him?’ chimed in Clara. ‘This silent partner of yours. Why’s he so shy?’

Mrs Gillyflower smiled a chilling smile. ‘Mr Sweet is always with us.’

Clara, as though expecting a grand entrance, looked about her. But no other soul entered the parlour. She took a step towards the imposing woman in black who towered before her.

‘Careful, Clara,’ warned the Doctor. ‘She’s dangerous. Like a cornered tigress.’

‘Flatterer,’ said Mrs Gillyflower. But then her forced smile fell and her face set hard as adamantine. ‘The process failed to work on you. Therefore you are a Reject. A dribbling, inconsequential nothing. And you must be eradicated! Like all who are unfit.’

‘All who are unfit. The old favourite. Only the perfect can survive! Everyone gorgeous and fit as a fiddle and probably blond and all absolutely, exactly the same.’

‘Paradise,’ breathed Mama.

‘Hell.’ The Doctor waved his bony hands in the air as though swatting away an inconsequential fly. ‘I’ve heard it all before, love. Change the wax cylinder.’

‘You dare to mock me?’

‘Yes! I dare!’ There was fury in the Doctor’s voice now, and self-righteous fury at that. ‘Would it be impolite to ask why you’re petrifying your workforce with diluted prehistoric leech-venom?’

A messianic glint crept into the woman’s eyes. ‘They are the future. Or, at least, the chosen few are. My loyal Pilgrims will have to accept their fate as … collateral damage. Mr Sweet and I cannot be responsible for everyone.’

The Doctor, his eyes darting from side to side, expecting an ambuscade of some sort at any moment, nodded. ‘You and your pal do seem to have a very close relationship.’

‘Oh yes, Doctor,’ chuckled Mrs Gillyflower. ‘Exceedingly close.’ So saying, she reached her hand to the high lace collar of her dress, there came a popping of hooks and eyes – ‘Symbiotic, you might say!’ – and she wrenched back the fabric.

What was revealed … Well, it is understandable that Clara let out an involuntary gasp of horror. For there, attached to Mrs Gillyflower’s throat, bristling with spindly legs, was a vile, leech-like creature, the size of a puppy. A sickly, glowing red, it had a rudimentary face like an unformed baby and protruding, black, glassy eyes. It turned its horrible little head towards the Doctor and Clara – and gurgled!