“Eldergrove,” Rivasoa said. Orfeus nodded, secretly glad for the clarification. She hadn’t seen many maps of this type and it was hard to instinctively associate the blue square grid with the growing organic green and colours of the city. Rivasoa pointed at a spot, blank against blue lines. “This place in the Catacombs has been generating far in excess of the required energy, and putting energy back into the grid.” She waved her hand and another map laid itself over the first one, this one shining in liquid lines of gold like a series of rivers. The energy of the city, flowing and rising, brightest at the height of the sun. “This wouldn’t be noticeable, except that it stopped, some three weeks ago.”

Orfeus squinted at the blip. “You think they moved base?” she said. “But wouldn’t it make more sense to trace some secret lab by seeing who used too much energy, not too little?”

Rivasoa shrugged. “Perhaps they’re overly conscientious in covering their tracks,” she said. She grinned just the tiniest bit. “Or they mean to do good. Many atrocities can begin with good intentions. And this could indeed be some entirely unrelated group of engineers or similar, or it might not be.” Her eyes, looking a more human brown, stared up into Orfeus’s in challenge.

Orfeus sighed. “Worth checking out,” she said, “but if that falls through, you owe me a guitar.”

Rivasoa didn’t dispute this, and Orfeus hid her surprise. She wouldn’t complain about a free guitar.

Catacombs beneath the city seemed an odd idea. Eldergrove was so much a city of above. The city towered, tree-laced buildings reaching up for the sky, stained glass solar panelling capturing the light and splaying it out in rainbows over distant streets.

But Rivasoa led her out into the streets, lightweight flyers and pedestrians passing them, and then to a grate. Rivasoa wiped her hands once, twice on her robes before she sighed, lifted the grate and climbed inside.

Orfeus followed her, curious. She bundled her cloak around her shoulders to keep any grime from getting on the rest of her clothes. Perhaps she should have worn a less pretty cloak.

In fact, down past the first slightly rusting ladder, it was very clean. Sanitation was an important part of any city, she supposed. Most human waste was treated, used to fertilise, recycled. These were more for stormwater.

“You said catacombs, not sewer drains,” Orfeus said.

Rivasoa shrugged. Her face had a slightly distant serenity. Orfeus thought it unlikely that she wasn’t bothered by being in such dripping and damp surroundings, and rather more likely that she was trying to distance herself from it, curling into the core of herself where nothing mattered as much.