I plunged a syringe through the rubber cap, drawing forth the milky liquid. I knew how to use needles from my work in the comparative-anatomy lab, but — my father’s pain-racked face flashed before me — I’d never injected a human being before. I ran to Klicks, my footfalls echoing in the steel-walled room, and bent over his crumpled form. He was still breathing, but shallowly, slowly, life apparently ebbing from him. I forced the needle through the thick wall of his right carotid artery, pumped the plunger down, and, never taking my eyes off him, slumped back against the door to our garage, the agony from my shattered nose growing, throbbing, multiplying.

It took a while — I’d lost track of the passage of time — but finally small amounts of blue jelly began to seep from Klicks’s temple. But something was wrong. It wasn’t undulating the way I’d seen the Hets move before, nor was it glowing. I rolled him over so that his bruised face was visible. One of his eyelids was stuck shut by dried blood, but the other fluttered open for a few seconds and he spoke in a rasping whisper. "You animals—"

I got an orange garbage bag and a spoon and, taking immense care not to touch it, began scraping away what little of the jelly had escaped. No more than two tablespoonfuls. The rest, dead or dying I hoped, seemed destined to remain inside Klicks’s head until his own antibodies and white corpuscles could deal with it as they would any other inert viral material.

I stuffed the bag into a metal box, went down the ramp to our outside door, and heaved the box as far as I could in the reduced gravity. It sailed out onto the cracked mud plain far below; in the moonlight, I saw it bounce twice when it hit.

I made it back to the medicine refrigerator, filled another syringe with Deliverance, and injected myself as a precaution. Then I opened the first-aid kit mounted on the refrigerator’s top and found a wad of white gauze. I held it tightly against the center of my face, stumbled back to my crash couch, and lay down on my back, the shift in posture sending daggers of pain through my head. I hoped and prayed with all my might that Klicks would pull through.

Tess gave me a big hug and a kiss when I got back to Toronto from Vancouver. I squeezed her, but my mind was elsewhere. We’d had a good marriage, as far as I could tell. We’d enjoyed each other’s company. Both of our careers had prospered. And the lack of children? Well, she had always said that it didn’t bother her, that she, too, felt they’d be an inconvenience, at odds with our lifestyle. And yet, in that other, original iteration of the timeline, she had left me for Miles Jordan. Klicks had always wanted kids. Was that part of the reason?

I wished to God that I’d never found that alternative diary. Ignorance really can be bliss. To think that my personal life was as tenuous and unstable as Ching-Mei said the universe itself was — it was enough to drive me crazy.

Ching-Mei had tried to explain how that other diary had come to be in my possession, how the memory wafer in my palmtop could have somehow swapped contents with the one the time-traveling Brandy had taken to the past with him. She spoke about shunting and Huang-Effect reversals and chaos theory, but she was guessing, really. It didn’t matter. The damage was done.

"How was the flight?" asked Tess, removing her arms from me.

"Typical Air Canada." My tone was cold, dry.

Tess’s eyes flicked across my face, looking, I guess, for the emotion underlying the weariness in my voice. "Sorry to hear that," she said at last.

I hung my coat in the hall closet and we made our way up to the living room. We sat together on the L-shaped couch, beneath a framed landscape painting done by Tess’s uncle, a not-bad artist who lived in Michigan. "Anything exciting happen while I was away?"

"Not really," she said. "Wednesday, I went to see that new James Bond film — I must say Macaulay Culkin makes a surprisingly good 007. And last night I had Miles over for dinner."

Klicks here? While I was away? "Oh."

"By the way, I balanced our bank account while you were gone. Why’d you charge your plane tickets on your MasterCard? Shouldn’t the museum have paid for those?"

Oh, crap. "Uh, well, the research was personal."

Tess blinked. "I beg your pardon?"

"I mean, it’s not important."

She looked up at me, searching. "Is everything all right?"

"Everything’s fine. Just fine."

Silence for a time, and then, softly: "I think I’m entitled to a better answer than that."

"Look," I said, and instantly regretted it, "I’m not giving you the third degree about what you did while I was away."

Tess smiled with her mouth, but I could see by the corners of her eyes that the smile was forced. "Sorry, honey," she said, false sun in her voice. "It’s just that I worry about you." Her eyes flicked over my face again. "I wouldn’t want you to have a midlife crisis and go running off with somebody else."

"I’m not the one who’s likely to do that, am I?"

She went stiff. "What do you mean by that?"

Christ, I was saying things that I shouldn’t. But if what we had wasn’t as special to her as it was to me, I had to know. I had to. "How was Klicks?" I said.

She was bristling. "He was fine, thank you very much. Pleasant. Nonargumentative. A damn sight nicer than you’ve been of late."

"I see. Well, if you prefer his company—"

"I didn’t say that." She slapped the arm of the couch, air forcing its way out of the plush armrest with a soft whoompf. "Jesus, you’re a frustrating man sometimes. You run off on some junket clear to the other side of the country. You’ve accused me twice now of, of infidelity. What in God’s name is wrong with you?"

"There’s nothing wrong with me." The same weary tone I’d used to describe the flight from Vancouver.

"The hell there isn’t." She looked up at me again and this time her eyes locked on mine. Those lovely green eyes, the same two haunting orbs that had fueled my fantasies before I’d worked up the courage to ask her out; the same two compassionate orbs that had helped me through the death of my mother, through the loss of that job in Ottawa, through so many tragedies; the same two intelligent orbs that had danced as we had held real discussions about things that had seemed oh so very important in our youth — war and peace and love and international relations and great moral controversies, she always quick with a point of view, me ponderously weighing the evidence, trying to decide what was right and what was wrong. Physically the eyes had changed only slightly over the years: their color was bluer now and there were fine wrinkles at their corners. But where once they had been great expansive windows for me, and me alone, to peer into her very soul, they now seemed silvered over, mirrored, reflecting back my own doubts and fears and insecurities, while revealing nothing of the mind that dwelt behind them.

"Do you still love me?" she said at last, a slight quaver to the words.

The question hit me with unexpected force. We didn’t speak of love, not openly, not anymore. That was a topic for those who were still young. We lived a peaceful coexistence: old friends who didn’t have to say much to each other; old shoes that grew more comfortable each time you put them on. Did I still love her? Had I ever loved her — the real her, the actual Tess — or had I only loved an image of someone else, someone I’d created in my mind, sculpted in my dreams? I realized, fast enough, fortunately, that this was one of those moments of truth, one of those significant butterflies, one of those decisions that could bend the timeline so severely that I’d never be able to correct its course.