“They do,” said Alex. Pebbles skittered down as they got the bike up over the edge of the bank. “Or at least the angels who live around here do. Illegal immigrants mean fresh energy supplies, without them having to go looking.” He remembered when Juan, one of the other AKs, had first showed them this route – and how he and his big brother Jake had encountered a border guard here once, smiling with angel burn and talking about how important it was to do the angels’ work.

Kara had been with them that time, too – an exotically beautiful AK with nerves of steel; both he and Jake had had crushes on her back then. “Idiot,” she’d said as they’d driven away, shifting gears with a tight, angry motion. Sitting in the back of the jeep, Alex had taken in her profile. And despite the easy banter the AKs usually shared, in that instant he could think of nothing at all to say to Kara – but had instinctively understood the mix of fury and sorrow that made her mad at the guard, as if getting angel burn were his own fault.

Now Willow looked slightly queasy at the thought of the predatory border angels. “Oh,” she said. He saw her throat move. “That’s – that’s really...”

“I know,” said Alex, understanding exactly how she felt. Unfortunately, there were plenty of angels in Mexico too, and had been even before the Invasion. There was hardly anyplace on earth now that he thought he could take Willow where she’d be really safe.

But he’d do his best – or die trying.

Nearby, he could just see the rough dirt track he remembered, heading off to the east. “Okay, that connects up with the highway eventually,” he said, climbing back onto the bike. “Or at least, it used to.” He hoped it hadn’t been washed out; struggling the Shadow over miles of no road at all seriously wouldn’t be his idea of fun.

Willow started to put on her helmet, but hesitated, playing with its straps. “Alex, are there any really big cities in Mexico? I mean – really big.”

He looked at her in surprise, taking in the worried lines that had appeared on her forehead. “Yeah, Mexico City. It’s one of the largest cities in the world. Why?”

She didn’t reply immediately. “I’ll tell you later,” she said at last. “But maybe we could find a place to stop soon, where we can talk.”

Apprehension tickled his spine. Whatever this was about, he didn’t much like the sound of it already – but hanging around a few feet from the border wasn’t the place for a long discussion. “Yeah, okay,” he said reluctantly, and pulled on his own helmet.