“You’re celebrating a man’s destruction,” Sarah said as they sat down to a Mexican dinner at Las Palmas on Eighty-sixth Street.

“I’m celebrating nothing of the kind. Hutch still has his job.”

“The biggest discovery in history, and you took it right out of his lap. You.”

He winced. “OK, I’m an ogre.”

“Ambitious bastard.” She smiled. “I wish I could punish you, Tom. God knows you need it. But the truth is I’m so damn relieved, I can’t see straight. Knowing that we’re out from under Hutch is—well, it does deserve a celebration.”

“I’m only an ogre when it comes to protecting your work.”

“Wipe that sincere smirk off your face, my love. It makes you look like a card sharp.”

“I think I resent that.”

“You love it.” She lifted her glass of beer. “Here’s to you, you bastard.”

“And to you, bitch.”

“Don’t call me names. I don’t deserve it.”

He could see a real argument developing out of this, so he said no more. The waiter returned and they gave their orders. Tom was surprised to hear Sarah order the biggest dinner on the menu; she normally subsisted on nibbles and snacks. Sometimes he thought a handful of birdseed a day was all she really needed. “At least you’re really hungry for once. That’s a good sign.”

“Developing neurosis. I’ll be as plump as a pigeon in a few years.”

“You don’t care?”

Her eyes flashed. “Tonight I want to eat. There’s nothing the matter with that.” She paused. “I’m ravenous, as a matter of fact. A second ago I felt like taking a salad right off that tray.” She gestured toward a waiter wheeling among the tables.

Their food was served promptly. For five minutes Sarah was silent, digging at her enchiladas and tamales. “Care for more?” Tom asked.

“Yeah!” He signaled the waiter and she ordered another round. An appetite was fine, but she was going to turn into a sausage if this kept up. “Got a pencil and paper?” she asked. “I’ve had some insights.”

“I’ll memorize them. Tell me.”

“One. We’re correct to assume that Miriam is evolved from a primate ancestor. She’s too close to us not to be. Two. We therefore need skeletal X rays so that we can determine which primate line is involved. Three. One thing is certain, she and her kind are in some sort of symbiosis with us, otherwise why would they keep themselves hidden? They take something from us we wouldn’t otherwise give.”

“Why does that follow?”

“What else would be their motive for secrecy? And it’s not a matter of being overlooked. It is deliberate. It must also be hard to do. It can’t have been easy to remain undetected for so long.” She paused, ate a couple of bites with birdlike speed. “I wonder what they take from us. I wonder if we’ll find out.”

Tom envied her the clarity of her mind. She had reduced the whole affair to two important questions.