I took a step forward. “Please,” I said.

More staccato gunfire from inside the gallery. It was almost as if the bullets were tearing into me; I could picture the shales shattering, the remains of Opabinia and Wiwaxia and Anomalocaris and Canadia that had survived 500 million years exploding into clouds of dust.

“Don’t,” I said, genuine pleading in my voice. “Don’t do that.”

“Stay back,” said the short-haired man. “You just stay where you are.”

I took in air through my mouth; I didn’t want to die — but I was going to, regardless. Whether it happened tonight or a few months from now, it was going to happen. I took another step forward. “If you believe in the Bible,” I said, “then you’ve got to believe in the Ten Commandments. And one of them” — I knew I’d have made a more convincing argument if I’d known which one — “says ‘Thou shalt not kill.’ ” I took another couple of steps toward him. “You may want to destroy those fossils, but I can’t believe that you’d kill me.”

“I will,” said the man.

More bursts of gunfire, counterpointed by the sounds of breaking glass and shattering rock. My chest felt like it was going to explode. “No,” I said, “you won’t. God wouldn’t forgive you for that.”

He jabbed the gun in my direction; we were maybe fifteen meters apart. “I’ve already killed,” he said. It sounded like a confession, and there was what seemed to be genuine anguish in his voice. “That clinic; that doctor . . .”

More gunfire, echoing and reverberating.

My God, I thought. The abortion-clinic bombers . . .

I swallowed deeply. “That was an accident,” I said, guessing. “You can’t shoot me in cold blood.”

“I’ll do it,” said the man the other one had called Cooter. “So help me, I’ll do it. Now you stay back!”

If only Hollus weren’t here in the flesh. If she were present as her holographic projection, she could manipulate solid object without having to worry about being harmed by the bullets. But she was all too real, and all too vulnerable — as were the other extraterrestrials.

Suddenly, I became conscious of the sound of sirens growing closer and closer, barely audible here, inside the museum. Cooter must have heard them, too. He turned his head and called out to his partner, “The cops!”

The other man reemerged from the temporary-exhibitions gallery. I wondered how many of the fossils he’d managed to destroy. He cocked his head, listening. At first he didn’t seem to be able to hear the sirens; doubtless the gunfire still echoed in his ears. But a moment later he nodded and gestured with his submachine gun for us to start moving. Christine got to her feet; the two Forhilnors lifted their torsos off the ground.

“We’re getting out of here,” said the man. “Each of you put your hands up.”

I lifted my arms; so did Christine. Hollus and the other Forhilnor exchanged a glance, then each lifted their two arms, as well. The Wreeds followed suit a moment later, each lifting all four arms and splaying all twenty-three fingers. The man who wasn’t Cooter — he was taller and older than Cooter — ushered us farther into the darkened Rotunda. From there we had a clear view out the glass-doored vestibule. Five uniformed Emergency Task Force officers were beetling up the outside stairs to the museum’s glass entrance. Two were brandishing heavy guns. One had a bullhorn. “This is the police,” called that cop, the sound distorted as it passed through the two layers of glass. “We have the building surrounded. Come out with your hands up.”

The man with the submachine gun gestured for us to keep moving. The four aliens were bringing up the rear, forming a wall between us humans on the inside and the police on the outside. I wished now that I hadn’t told Hollus to land her shuttle out back on Philosopher’s Walk. If the cops had seen the shuttle, they might have realized that the aliens weren’t the holographic projections they’d read about in the newspapers but instead were the real thing. As it stood, some hotshot might assume that he could pick off the two armed men standing behind the aliens by shooting through the projections.

We made it out of the Rotunda, up the four steps to the marble landing between the two stairwells, each with its central totem pole, and then —

And then everything went to hell.

Coming quietly up the stairwell on our right from the basement was a uniformed ETF officer, wearing a bulletproof vest and brandishing an assault weapon. The cops had cleverly made a public stand outside the main entrance while sending a contingent up through the staff entrance from the alleyway between the ROM and the planetarium.

“J. D.,”shouted the man with the buzz cut, catching sight of the cop, “look!”

J. D. swung his gun and opened fire. The cop was blown backward, down the wide stone steps, his bulletproof vest being put to the test as it erupted in numerous places, bleeding out white fabric stuffing.

While J. D. was distracted, the cops on the front steps had somehow opened one door — the one at the far left, as they faced it, the one that was designed for wheelchair access; perhaps the ROM security guard had given them the key. Two cops, safe behind riot shields, were now inside the vestibule. The inner doors didn’t lock — there was no need for that. One of the officers reached forward and must have touched the red button that operated the door for handicapped patrons. It swung slowly open. The cops were silhouetted by streetlamps and the revolving red lights of their vehicles out on the street.

“Stop where you are,” shouted J. D. across the Rotunda, its wide diameter separating our motley group from the cops. “We have hostages.”

The cop with the bullhorn was one of those now inside, and he felt compelled to keep using it. “We know the aliens aren’t real,” he said, his words reverberating in the darkened, domed Rotunda. “Put your hands up and come out.”

J. D. jerked his large gun at me. “Tell them who you are.”

With the shape my lungs were in, it was hard for me to shout, but I cupped my hands around my mouth and did the best I could. “I’m Thomas Jericho,” I said. “I’m a curator here.” I pointed at Christine. “This is Christine Dorati. She’s the museum’s director and president.”

J. D. shouted. “We get safe passage out of here, or these two die.”

The two cops hunkered down behind their riot shields. After a few moments of consultation, the bullhorn erupted again. “What are your terms?”

Even I knew he was stalling. Cooter looked first at the southern staircase, which led up, and then at the northern staircase, which led both up and down. He must have thought he saw something move — it could have been a mouse; a giant, old building like the museum has plenty of them. He fired a shot down the northern staircase. It hit the stone steps, jagged shards went flying, and —

And one of them hit Barbulkan, the second Forhilnor —

And Barbulkan’s left mouth made a sound like “Ooof!” and his right mouth went “Hup!”

And a carnation of bright-red blood exploded from one of his legs, and a flap of bubble-wrap skin hung loose from where the stone fragment had hit —

And Cooter said, “Holy God!”

And J. D. turned around, and he said, “Sweet Jesus.”

And they both apparently realized it at the same moment. The aliens weren’t projections; they weren’t holograms.

They were real.

And suddenly they knew they had the most valuable hostages in the history of the world.

J. D. stepped backward, moving behind the group; he’d apparently realized he’d been insufficiently covering the four aliens. “Are you all real?” he said.

The aliens were silent. My heart was jumping. J. D. aimed his submachine gun at the left leg of one of the Wreeds. “One burst from this gun will blow your leg right off.” He let this sink in for a moment. “I ask again, are you real?”