He peered out from the end of the alley to check that the BlackPath was empty. Keeping to the shadows, he led the bears towards the tall building. The small flat-face dens gave way to bigger structures with blank windows or no windows at all; there was a sense of emptiness and desolation around him, and the reek of oil grew stronger still.

Lights on the outside of the buildings lit up a scatter of flat-face rubbish blowing across the BlackPath. A sheet of paper hit Toklo in the face; the wind plastered it to his head and chest.

‘That’s disgusting!’ the grizzly cub complained, halting to claw himself free of the sheet. ‘It stinks of flat-faces.’

‘I know,’ Kallik agreed sadly. ‘I hate it here.’

‘Then we’ve just got to get out of here as fast as we can,’ Ujurak tried to encourage them. His paws tingled at the thought of padding over grass again, and dipping his snout to take a drink of pure river water. But soon there might not be pure water anywhere.

Ujurak remembered his vision in the hospital, after he had smeared the oil Janet brought him on his fingers. He had felt it streaming out from his body, swamping it, filling his mouth and nose, and flowing onward, unstoppable, until it had engulfed the whole world.

‘It’s going to get so much worse,’ he whispered.

Gradually the tall building grew closer, until the bears stood in its shadow. It reared up into the sky, taller than the tallest tree; all its windows were dark. The BlackPath curved past it, flanked on both sides by more flat-face dens. In every direction it was the same. Wherever Ujurak looked, the world was filled with structures of stone and metal.

‘Well, what do we do now?’ Toklo growled, swinging his head round in disgust. ‘This is where the flat-face cub told us to go, but we’re nowhere nearer to finding the way out.’

‘We could be stuck here forever!’ Kallik whimpered.

‘No, we won’t be,’ Lusa said. ‘We’ve got to keep looking. It can’t be far now.’

‘Do you ever stop being cheerful?’ Toklo muttered. ‘It’s so annoying.’

‘Well, you can be pretty annoying yourself!’ Lusa retorted.

‘Don’t fight,’ Ujurak said, moving to Toklo’s side and resting a paw on his shoulder. ‘I’ll find the way out, but first we’ve got to look for somewhere you can hide.’

With the bears just behind him, Ujurak began to skirt round the tall building. Wind whistled past with a mournful sound, stirring up more dust and rubbish. Briefly Ujurak froze as he heard the throaty roar of a firebeast in the distance, but it faded without coming into sight. He thought this was the loneliest place he had ever been, worse than the remotest mountain.