Joe and Jackie looked at each other. Their expressions showed that they understood what Helen was saying.

A.J., however, was obviously in the dark. "Um, what's the problem? One second you're practically ready to start writing your Nobel Prize speeches. The next minute you're acting as if Jack the Ripper just came in."

Joe pointed at the image. "If Helen publishes a full report on that, it'll probably wreck her career."

"Well, not quite that," Helen said, shaking her head. "I've got tenure, after all, so I'd keep collecting a paycheck. But it would most likely get me relegated to the status of a crackpot. At least in the eyes of most of my colleagues."

"So screw 'em," A.J. snorted. "They don't believe you, too bad for them. It's right there in front of 'em!"

"A.J., that may work for you-your imaging work deals with real solid stuff that no one can argue with. But paleontologists are more in the position of detectives trying to figure out what happened with only a handful of clues."

Joe's tone of voice was that of a parent trying to explain the facts of life to a stubborn eight-year-old. Given that A.J. was, in point of fact, not more than a year or two younger than Joe, Helen found it somewhat amusing.

But she could see that A.J. was beginning to bridle at the tone, so she intervened.

"Look, A.J., it's just a fact that paleontologists tend to be very conservative, in a scientific sense. Nor, by the way, do I say that critically. Joe's right, you know. We do have to work from mostly disconnected facts, just like detectives-and the fossil record is about as far removed as you can get from what anyone in their right mind would call a 'perfect crime scene.' Our data is hundreds of millions of year old, and fragmented to boot. There's so much gray area-so many different ways anything can be interpreted-that members of my profession generally look cross-eyed whenever somebody comes up with a sweeping proposition. Especially one that flies completely in the face of previous findings."