"We do—"

"So how can you—"

"But we not aware that time travel is possible," said Diamond-snout, overtop of Klicks. "Last night, that black and white disk that crashed into the ground. That was your vehicle for time displacement?"

"The Sternberger, yes," said Klicks. "Its technical name is a Huang temporal phase-shift habitat module, but the press just calls it a time machine."

"A time machine?" The reptilian head bobbed. "That phrase appeals. Tell how it works."

Klicks appeared irritated. "Look," he said. "We know nothing about you. You’ve crawled around in our heads. What the hell are you?"

For the first time, I noticed the way the troodon blinked, an odd gesture in which it closed its left eye, opened it, then briefly closed its right. "We entered you only to absorb your language," Diamond-snout said. "Did no harm, yess?"

"Well—"

"We could enter you again to absorb additional information. But time-consuming process. Clumsy. Language center obvious in brain structure. Much mass devoted to it. Specific memories much harder to faucet. Faucet? No, to tap. Easier you tell us."

"But we could communicate better if we knew more about you," I said. "Surely you can see that a common set of references would make it simpler."

"Yess. See that and raise you — No, just see that. Common reference points. Links. Very well. Ask questions."

"All right, then," I said. "Who are you?"

"I am me," the reptile said.

"Great," muttered Klicks.

"Unsatisfactory response?" asked the theropod. "I am this one. No name. Name not link."

"You’re a single entity," I said, "but you don’t have a name of your own. Is that it?"

"It is that."

"How do you tell yourself from others of your own kind?" I asked.

"Others?"

"You know: different individuals. One of you is inside this troodon; another is inside that one. How do you distinguish yourselves?"

"I here. Other is there. Easy as 3.1415."

Klicks hooted.

"What are you?" I asked, annoyed at Klicks.

"No link."

"You are an invertebrate."

"Invertebrate: animal without a backbone, yess?"

"Yes. What are your relatives?"

"Time and space."

"No, no. I— Damn. I want to know what you are, what you evolved from. You’re unlike any form of life I’ve seen before."

"As are you."

I shook my head. "I’m not too dissimilar from the dinosaur you are now inhabiting."

"Dinosaur is efficient creature. Strong. Keen senses. Yours are dull by comparison."

"Yes," I said, irritated. For years, I’d explained to people that dinosaurs weren’t the sluggish, stupid creatures so often portrayed in cartoons, but somehow I didn’t enjoy hearing the same sentiments expressed by a reptilian mouth. "But we are more similar than different. Each of us is bipedal — that means we each have two legs—"

"Bipedal links."

"And we each have two arms, two eyes, two nostrils. Our left sides are nearly perfect mirror images of our right sides—"

"Bisexual symmetry."

"Bilateral symmetry," I corrected. "Clearly, the dinosaur and I are related — share a common ancestor. My kind did evolve from ancient reptiles, but there are other creatures about, tiny mammals, that are even more closely related to us. But you — I’ve studied the history of life since it began. I don’t know of anything similar to you."

"Its body is completely soft," said Klicks. "Creatures like that might go undetected in the fossil record."

I turned to him. "But intelligent life arising millions of years before the first human? It’s incredible. It’s almost as if—"

I’d like to claim that I was about to state the correct conclusion, that at that instant I had pieced together the puzzle and had realized what was going on. But my next words were drowned out by a great roaring clap, like thunder, followed by several bellowing dinosaur calls and the cries of flying things startled into flight. I recognized the noise, for my home was due south of Pearson International Airport and, despite the complaints from me and my neighbors, it had become part of the background of our day-to-day lives ever since Transport Canada had approved inland supersonic flights of the Orient Express jetliners. High overhead, three tawny spheres moving at perhaps Mach 2 or 3 streaked across the sky. At the least, they were aircraft, but I knew in an instant that they were much more than that.

Spaceships.

"You under a misapprehension operate," said Diamond-snout once the sky had stopped rumbling. "We are not from this planet."

Klicks was flabbergasted, which pleased me no end. "Then where?" I said.

"From — home world. Name I not find in your memories. It’s—"

"Is it in this solar system?" I asked.

"Yess."

"Mercury?"

"Quicksilver? No."

"Venus?"

"No."

"Not Earth. Mars?"

"Mars — ah, Mars! Fourth from sun. Yess. Mars is home."

"Martians!" said Klicks. "Actual fucking Martians. Who’d believe it?"

Diamond-snout fixed Klicks with a steady gaze. "I would," it said, absolutely deadpan.

The traveler’s diary — the one that purported to tell the story of a trip back to the end of the Mesozoic Era — had to be a fake, of course. It had to be. Oh, it superficially resembled my writing style. In fact, whoever had put it together had obviously read my book Dragons of the North: The Dinosaurs of Canada. In preparing the manuscript for that book, I got sick of all the italics. See, Linnaeus established that biological naming would be in Latin, and non-English words are usually italicized in modern typesetting. Plus, Linnaeus said the genus part of the name should always be capitalized: Tyrannosaurus rex. Since there are no common English names for individual types of dinosaurs, popular books on the subject have slavishly followed this convention so that almost every tenth word is italicized or capitalized, bullying the reader’s eye.

I’d taken some flak from my colleagues for it, but in Dragons of the North I chucked out that convention. The first time I mentioned some Mesozoic critter, I’d use the Linnaean standard, but thereafter I’d treated the name as if it were a common English term, just like "cat" or "dog," uncapitalized and unitalicized. Well, whoever had cobbled together this bogus diary had copied at least that much of my style.

Although I never used it, my palmtop had come bundled with a grammar-checking program. I had my diary from last year still stored on the Toshiba’s built-in optical wafer, so I called that up alongside the fake traveler’s diary. With each document in a separate window, I let the grammar checker run a stylistic comparison between them. The program produced a dozen charts — including "Flesch-Kincaid grade level," "average number of words per sentence," and "average number of sentences per paragraph." The conclusion was inescapable: both diaries, mine and the supposed time traveler’s, were in almost identical styles.

The grammar checker had a feature that I’d never before found a use for: the ability to output an alphabetized list of all the words in a document. I had it do that for both diaries, then filtered and piped between the two lists until I had a new file containing only the words in the traveler’s diary that did not appear in my own diary from last year. I thought perhaps the forger would have tripped up by using words that weren’t part of my vocabulary.

I scanned down the list. There were a lot of words, including "archaeopteryx" and "hawked," but almost all were ones I could see myself using. There were one or two — such as "firmament" — that didn’t sound like me at all, but, then again, I did have Roget’s Thesaurus loaded onto my optical drive.