Free Boundary 2: Threshold by Eric Flint, Ryk Spoor

a grin; there was, indeed, something childlike about the man which she found irresistible, and that quick flash of simple joy was part of it.
    "Find it? Of course I'll find it," the blond sensor expert said, the momentary drop into negativism over. "I didn't say I couldn't find it, just that it's not going to be easy. Unless I get lucky. Which, since Helen's here, I just might." She gave him an affectionate poke at the mild double-entendre.
    "You know, A.J., you actually discovered Phobos Base before the Faeries ever went inside," Jackie pointed out. "The internal-structure map showed a lot of the tunnels. You—and the rest of us—just would never have thought of what they really were beforehand. That's not true now, though. So why not just do the same internal mapping for Ceres?"
    "Because Ceres is big. Big. Big-biiiig-big. Big—BIIIIIG!" A.J. did a Warner Brothers' set of caricature gestures showing how BIIIIIG he meant while he voiced the sentiment. "I could, with a lot of pulses and overpowered emissions and processing, manage to map out a lot of the interior of Phobos, yeah. Using all the Faeries and several hours. On a chunk of rock about one-fiftieth as far across. Even with the better power and sensor capacity I've got here, there's no way I'm getting a signal through Ceres." He looked momentarily abstracted. "Well, not a wireless one. If I put some sensors down and start doing impact events on the other side I could get seismographic and vibration data . . . but that'd require having a lot of spare stuff to throw, or a lot of explosives—a lot more than we have. Anyway, I'm going to do my best—GPR data and all that might help, depending on what stuff they made their installation out of here. Remember that some of their stuff was practically invisible to me, and other parts blocked everything. But we might come down to a remote foot-survey. Still, no point wasting time. I'm already on it."
    A.J. turned back to his console; Helen could see him getting ready to settle in for one of his legendary marathon sessions.
    "I'll bring you something for dinner later," she said, glancing at the others. They all clearly recognized the symptoms. "That good?"
    "Yeah, that'd be great. Haven't done this for a while. Time to get really down to business." Thin screens rose up around his station, blocking him from view.
    "Why does he stay there?" Jackie mused as they climbed to the hab ring. "I mean, he could control all that stuff from your cabin, or even one of these connecting shafts, just as easily as he could on the bridge."
    "Because he's A.J. Baker, certified genius at work," Helen answered with a laugh. "No, really. Partly he does it because he finds it too easy to be distracted in more comfortable surroundings. But . . ."
    Jackie smiled in understanding. "But he's also a show-off, and no one will see how hard and dedicated his work is unless he's somewhere public." Her tone was more amused than critical; Jackie liked A.J., no matter what his faults.
    "You've known him as long as I have. Never thought about dating him?" Helen asked suddenly, curious.
    "Date A.J.? God, no offense, Helen, I'm glad you're happy and all, but Jesus Christ, no. It'd be like dating my hyperactive little brother. Aside from being admittedly very cute, I can't understand what you see in him—romantically, that is. Joe was much more my speed, but it never really jelled."
    "And once Madeline showed up, that was it."
    Jackie grinned. "Oh, I wasn't possessive over him. Like I said, it never jelled. But I admit that trying to compete with Maddie would be a lost cause anyway."
    "So . . . no one serious in your life?"
    The younger woman shook her head, dark hair restrained in a tight ponytail. "Not really. Well . . ." She looked slightly embarrassed. "I did have a crush on Dr. Gupta for a while."
    "No need to be embarrassed about that. The man has presence." Helen stepped off the central ladder and made room for Jackie. "I admit to having had