Emilie and the Sky World by Martha Wells

Dr Marlende made his preparations. Emilie spent the time ignoring Efrain and getting a quick tutorial in how to signal for help in lamp and wireless code from Daniel. Or at least, she tried to ignore Efrain. He came into the compartment where the signal lamp was mounted, where Emilie and Daniel sat at a little table that folded down from the wall. Daniel had marked the codes on paper and Emilie was tapping them out by knocking on the table. Cobbier was still working the signal lamp, though Daniel was due to take over for him in a few minutes.
    Efrain stood there a moment at Emilie’s elbow, looming in annoying younger-brother fashion, then said, “Can I talk to you?”
    Emilie didn’t look up. “No, I’m busy. I need to learn this.”
    Efrain hovered for a time, then finally left.
    Emilie saw Daniel’s expression and heard him draw breath to speak. She said, “No, I have no intention of making up with him, so I’m a terrible, mean person.”
    “I think you’re a very upset person,” Daniel said. He glanced up at her. “Has he really been awful to you?”
    Emilie started to say yes, then thought it over. Daniel deserved a better answer. A more honest answer. “He probably doesn’t think he has.”
    “I’m not giving you advice.” Daniel held up his hands, as if to ward off any accusation of giving advice. “But what we’re doing is not safe, and… It’s just a good idea not to leave things in a way you might regret later.”
    “I know,” Emilie grumbled. She really did know. But it felt like the hardest thing in the world.
     
    The first thing they had to figure out was how they were going to get aboard. From this angle, the only openings in the aether-sailer were the window portals, and those appeared to be covered with glass or some other transparent material. They needed to find some sort of hatch.
    By stopping and starting the engine, and turning the aether rudder at the stern of the airship, Dr Marlende maneuvered around and brought the airship closer to the aether-sailer. Watching from the port in the control cabin, Emilie held her breath, but the other ship still didn’t seem to notice they were there. The airship dropped slowly, the curved wall of the far larger aether-sailer looming over it. This close Emilie could see scratches and pits in the dull silver metal, as if the ship had been struck by wind-blown debris, or had spent years traveling in heavy weather. “It’s old, isn’t it?” Emilie said aloud. For some reason, that seemed strange, as if part of her had assumed the aether-sailer had sprung into being just before the professor had detected it. “Do you think it’s been traveling for a very long time?”
    It was the professor who answered, watching the view out the port with her arms folded. “It’s a possibility. We’ve assumed that the concentric world theory is correct, and this ship is a visitor from the world just above ours. But if it’s designed for long aether-current voyages, it could have traveled through many such levels to get here.”
    That was rather encouraging, Emilie thought, as the airship followed the curve of the lowest hull. Pirates or other people who wanted to cause trouble would surely stick to targets close to home. The only people who would have reason to travel through many different worlds were explorers and philosophers. You hope, she told herself. It didn’t explain why the aether-sailer seemed to be ignoring them.
    “There doesn’t seem to be anything at all down here,” Lord Engal said from the other port. He sounded disappointed. “Perhaps… Wait. There, toward the middle. There’s a round shadow.”
    Miss Marlende, manning her side of the control board, stood up from her seat to look. “Move forward, Father. About ten degrees.”
    Emilie leaned against the port and craned her neck. All she could see was more curving pitted metal; the strange light filtering through the aether current reflected off it in shafts of blue. The airship