Yaz opened her eyes. The creature was grimacing at her in distaste.

‘Not suitable,’ it spat. ‘Smell’s wrong. Not suitable at all.’

It turned, its thick tail lashing out at her legs and sending her sprawling. She watched as it scampered across the room to rejoin the pack. The creatures had completely overpowered Ace, beating her almost unconscious as she clutched the bat to her body, pinned to the floor.

The Ratt that had dismissed Yaz pushed through the tangle of bodies and loomed over Ace’s prone body, its nose twitching excitedly.

‘Ahhh …’ Its eyes closed in an expression of delight.

With a wet coughing sound it unleashed a wad of mucus over Ace’s face, making her retch. She tried to twist away from the stream of thick matter that splattered from the creature’s mouth, but the pack had her held securely.

The creature wiped its lips, then turned to stare at Yaz with an evil gleam in its eyes. ‘Such a generous donation this one makes.’

Yaz watched as a sickly green glow started to envelop Ace’s prone body, spreading rapidly to encompass the surrounding rat creatures.

‘No!’ Yaz fumbled with the homing beacon at her neck, but it was too late. There was a sudden flare of light, and when it had faded Ace and the rat creatures had gone.

Yaz got to her feet, making her way carefully around the ragged hole that had been blown in the apartment floor. A cold wind was blowing in through the shattered windows, and in the distance Yaz could hear the undulating sound of sirens getting closer and closer.

She pulled her phone from her pocket and dialled the Doctor’s number in the TARDIS.

‘Doctor? Graham?’

Graham’s eyes were glued to the screen, which was again showing the radar sweep of the Doctor’s monitoring system. He was listening out for any sounds of approach, or suggestion of danger. The temperature seemed to have risen, and the smell in the air was changing, becoming sourer; damage done by the Astingir’s forced entry, he guessed. Little shivers and shudders seemed to run through the floor and walls, whispers and groans sounded in the floor. It’s your imagination, he told himself; and then told himself firmly to believe that.

‘Doctor! Graham?’

The voice carried from the TARDIS.

It was Yaz.

‘Yaz?’ Graham dithered for a moment – he was meant to watch for the red light at all costs, but now Yaz was calling in, something had happened. If he went to her, and Ryan was taken, and he wasn’t there to throw the lever …

‘Come on, Doctor.’ Yaz sounded distressed, urgent. ‘Pick up, please!’

Graham turned and charged inside the TARDIS, hit the phone link. ‘Yaz, love, it’s me,’ he blurted. ‘You all right? What’s happening?’

‘They didn’t take me!’ Yaz cried. ‘I was covered in that slime but they still didn’t take me.’

‘Who?’