“This is where they grow Mistrun tea,” Rufus said as they passed through the valley. “One of the finest teas in the world. Costs a lot, back home.”

Mistrun was the name of the river they were sailing down, unimaginatively named for its signature mist. According to Rufus, the source of the river was the largest water aperture in the desert.

“It’s not a natural river?” Jason asked.

“It depends on what you think of as natural,” Rufus said. “There’s an oasis with the aperture at the bottom of a lake. All this water flows from there.”

The most exciting point of the journey came when the river reached a deep gorge. The river should have spilled into the gorge, but instead it flowed into a humungous aqueduct that spanned over the lengthy gap. A hundred metres wide and three hundred metres across, the aqueduct carried the river and those who sailed it over the gorge to continue along on the far side. The aqueduct was built entirely from green marble.

“This is crazy,” Jason said as they crossed over. Even at a hundred metres wide, the aqueduct was thinner than the river. This noticeably sped up the flow of the river and the speed of their barge. Jason looked out at the gorge, but they weren’t close to the edge and he couldn’t see much over the raised lip of the aqueduct. All that was visible was an unnerving expanse of sky.

“Sky River Gorge,” Gary said enthusiastically. “I tried to get them to go closer to the side so we could look over, but they said no.”

“How deep is this gorge?” Jason asked. “The pillars holding this thing up must be huge.”

“Interestingly,” Rufus said, “this aqueduct has no structural support other than the two ends.”

“That doesn’t sound safe,” Jason said.

“Rufus, I think you were wrong,” Gary said. “You did make too much preparation.”

“You do kind of sound like a tour guide,” Jason said.

“What’s a tour guide?” Rufus asked.

“Someone who gets paid to stand near interesting things to tell people about them,” Jason explained.

Farrah laughed.

“Rufus, I think you missed your calling,” she said.

“What’s wrong with teaching people about interesting places?” Rufus asked. “It sounds like a noble vocation. If there was one here, for example, they could point out that no one knows who built this aqueduct.”

Gary groaned.

“Why would you learn that?” he asked. “How does it help us with missions?”

“You carry on, Rufus,” Jason said. “I’d like to hear it.”

“Thank you,” Rufus said. “The aqueduct was already here when people first moved to this region, some three and a half centuries ago. At least, that’s when it was permanently settled. There is some evidence of people being in this region before, but no historical record of who or when.”

“Except for that old order of assassins,” Gary said.