In the end, Fitz didn't find Compassion. Compassion found Fitz.

He'd wandered aimlessly at first, back through the marketplace and town until he'd come out on to the seafront.  It reminded him of the places he'd been as a kid - Brighton maybe, or Weymouth - but everything was on a much grander scale, the buildings gleaming and seamless, and most striking of all there was no litter.  It all looked so perfect, so serene, that Fitz momentarily forgot his quest and crossed the road to look at the beach.  He'd taken in the view for a few minutes, marvelling at the yachts and cruisers moored in the harbour and at the rippling green expanse of ocean, before he remembered he was supposed to be looking for Compassion.

He'd started wandering along the pavement beside the beach unable to keep his eyes from the sunbathers, even though many of them weren't even human.  He'd rarely seen such a variety of alien life - tentacles, flippers, feelers, all crowded the beach; here, at least, were people determined to have fun.  When he did eventually clap eyes on a pair of naked, female, human breasts it felt like coming home, and he'd had to restrain himself from breaking into a round of hearty applause.  He was contemplating a bevy of bipedal dolphin-like creatures, splashing and laughing at the water's edge, wondering if they were humans who who'd decided to become dolphins or dolphins who'd decided to become human, when a hand clamped down on his shoulder.

He turned.  It was Compassion, her face still hidden beneath her hood.  'Fitz, we have to get away from here.  Something bad coming.'

Fitz was relieved to see her.  'Where have you been?  Are you OK now?'

Compassion shook her head.  'No.  Come on, we have to leave.'

Then Fitz saw something out of the corner of his eye.  Something falling.  There was a splash from out at sea, a few shrill cries from the dolphin creatures.  People were getting up, pointing at the thing that was bobbing in the sea.

Fitz shaded his eyes.  A black spiny object, for all the world like a mine.  As he watched, more of them fell out of the sky with eerie whistling shrieks.

Fitz pointed.  'Is that what you mean?'

Compassion nodded.  'Yes.'

A flicker of movement above.  Fitz looked up.  And gasped.  The sky was black with oval shapes, blotting out the sun, dappling the white sand with shadow.  From them the spiny things were dropping like seeds, whistling and splashing into the sea.  Now black gas was surging out of the objects in the sea, spreading incredibly quickly as if it was replicating within itself, rolling over the top of the waves, heading for the shore.  People were screaming, climbing over the sea wall, pushing past Fitz and Compassion.  The dolphin creatures ran past, chirruping and squeaking in agitation.

Fitz stared at the black gas as if hypnotised.

'What is that stuff?'

'Some sort of gas, but there's something more.  Something -'

'The Doctor,' cried Fitz.  'We gotta get back to the pie shop.'

'We'd never make it,' said Compassion.

It was true.  Now the entire seafront was a thick mass of black, as if a thundercloud had fallen to earth, and it was surging up the beach towards them.  Fitz watched as someone fell, further along the shore, their cries abruptly cut off as the black cloud rolled over them.

'Time to go,' said Compassion, and turned herself into a doorway.

Fitz felt oddly detached.  It was almost as if he'd been expecting this.

Then it began to rain.

A drop landed on the flagstones before Fitz.  It hissed angrily, burning a tiny crater in the concrete.