“But what about when we go back inside? We can’t stay out here forever.”

“I don’t have an answer for you. We’ve got enough air for six or seven hours. We have to think of something — soon.”

We had to think of something. But we didn’t succeed. My mind stayed blank. McAndrew is a superbrain, but not when it comes to this sort of problem. After half an hour floating free not far from the ship, he shook his head.

“It’s got me beat. But this is silly. There’s no point in sitting here doing nothing. We might as well get on with the measurements.”

He placed one mass detector in my care, with its inertial position sensor tuned to the Hoatzin as reference, and started to steer me under his direction from one fixed place to another, while he moved himself in constant relative motion. He apparently knew exactly what he wanted. That was just as well. My own thoughts were all on the situation aboard the ship. What would we do when our air ran low?

I worried that problem with no result while McAndrew made four straight-line passages, right through the middle of the kilometer-wide region that he described as shadow matter. The mass detectors confirmed that something was there. I saw absolutely nothing.

On the fifth passage through, McAndrew paused halfway. He called to me to move closer, while he carried his own detector through a complicated spiral in space. At the end of it he left his mass detector where it was, flew across to me, and examined the recording on my instrument.

“Well, I’m damned,” he said. “Jeanie, I think you were right. Stay there.” And leaving me mystified and feeling about as intelligent as a marker post, he flew away. This time he moved his mass detector through an even more complex path in space, pausing often and proceeding very cautiously.

“I’ve still no idea what this is, overall,” he said when he came back. “But I’ll tell you one thing for sure. There are structures in shadow space that I’ve never met in our spacetime.”

“Right about what?” I asked. “You just said I was right. But what was I right about?”

“That we ought not to set the ship in the middle of that, without knowing more about it. I’m seeing evidence of gravitational line singularities, or something very like them, running across the shadow matter region. You don’t find those in our universe. If we had flown in too close to one of them, we might have found ourselves in trouble.”

“You mean we’re not in trouble now? With Lyle and Parmikan waiting for us.”

“I’ve been thinking about that, too.” He came close, and his face was earnest and unshaven within his visor. “I think you’re overreacting. There’s no evidence at all that Lyle and Parmikan even knew there was a Dummy’s Delight set up in the Hoatzin’s computer. And certainly there’s no evidence they mean us any harm. But anyway,” he went on, before I could interrupt, “one thing’s for sure: When we go back in the lock, I should enter first while you stay outside. I know both of them, they respect me, and they’ll not do anything to hurt me.”

McAndrew is a pathetically bad liar. I didn’t argue with him. But when we were a few meters from the lock I said, “You’ve got it backwards. I’m the one they won’t hurt, because they need a pilot to get home. And you don’t know how to work our only weapon. Don’t stand too near the hatch of the lock.”

I dived for the airlock, pulled myself inside, and swung it closed in one movement, leaving Mac to bang on the outside. While the lock was filling with air I did a little work of my own. It required that three separate safety procedures be overridden, so it took a few minutes. At last I moved forward to open the inner lock door, then jumped back at once to stand by the outer one.

I didn’t know what I was expecting. Lyle and Parmikan, going about the normal business of the ship, with a stack of messy chores ready for me? Or waiting to complain that I had for no reason at all wiped out a program that one of them had set up in the computer, for a wholly innocent purpose?

What I hadn’t expected was a projectile weapon, held in Van Lyle’s hand and pointed right at my belly-button. I rammed my left fist down on the lock control, as the thought flashed through my head that there should have been a more thorough luggage inspection when we boarded the Hoatzin.

I moved as fast as I could, but they had been ready and waiting. I was too slow. Lyle pressed the trigger.

As he did so two things happened. Parmikan smacked at Lyle’s hand and screamed, “Don’t kill her! We need her to get us back.” That saved me, spoiling Lyle’s aim. In the same moment the outer lock door, its final safety trigger broken by the force of my fist, blew outward in a rush of air.

I flew out with it, knowing that my last-ditch plan to fight back had failed. I was hit. And my secret weapon was useless, because Lyle and Parmikan were already wearing suits.

I felt the fainting weakness that comes with a sudden drop of blood pressure. Then my suit resealed, and a few seconds later McAndrew was grabbing at me to halt my spin. He had followed me as I emerged in that crystal cloud of cooling air.

I felt pain for the first time, and looked down. Half the calf of my left leg was missing. The automatic tourniquet had cut in and tightened below the knee. The flow of blood from the wound had already stopped. I would live — if we somehow survived the next few minutes.

Which didn’t seem likely. Lyle and Parmikan had emerged from the lock, and Lyle still had his gun. He raised it. And shot me again.

Or he would have done, had he been the least bit familiar with freefall kinematics and momentum conservation. Instead the recoil of his gun sent him rolling into a backward somersault, while the bolt itself flew who knows where.

Before Lyle could sort himself out and fire again, McAndrew was dragging me away, using his suit propulsion system at maximum setting to carry both of us along. One nice thing about Mac, he didn’t need much data to form a conclusion.

“Don’t try a long shot.” That was Parmikan to Lyle, over the suit radio. “She’s injured. Get in close. Then we finish him and grab her. But don’t kill her — she’s taking us home.”

“I won’t kill her.” That was Lyle, the white plaster on his nose vivid through the suit’s visor. “Not ’til I’m done with the bitch. She’ll wish she was dead before that.”

They were coming after us, knowing that we had no place to hide. It was our misfortune to find ourselves, weaponless and pursued, in the emptiest quarter of known space. Nowhere to run to, and soon we would be out of air.

McAndrew was retreating anyway, dragging me along with him, but not in a simple, straight-line run. We were zigzagging up and across and sideways, rolling all over the sky; which made good sense if you were trying to evade being shot, and no sense at all when your enemy had just declared that he would not shoot until he got close.

Then we stopped dead. Mac glanced all around him, sighting for Parmikan and Lyle, the two mass detectors just where we had left them, and the shape of the Hoatzin, further off. He lifted us a few meters upward, and halted again.

“Here we are, then,” he muttered. “And here we stay.”

Lyle and Parmikan hadn’t moved while Mac and I had been corkscrewing our way around in space. Now they started towards us. Soon I could see their faces, white in the reflected glow of the visors’ built-in instruments.

Still McAndrew didn’t move. The feeling of distance and unreality that had swamped me the moment I was shot started to fade. At last I was scared. But when I started my propulsion system, ready to take off again away from the advancing men, Mac held out his hand to stop me.