Killer Move

“I thought I should wait until I had some clue about how to explain the pictures being on my laptop,” I said, aware of how lame an excuse this was.

“Hmm,” she said, and then ducked her head closer to the screen. “This interests me.”

“What?”

Her hands flashed around the keyboard for a few seconds, causing small, semitranslucent windows to pop up and disappear almost too quickly to see. “You mind?”

“Mind what?”

Then the first picture was back up on-screen. A couple of finger taps, and it jumped in size—first to fill the entire screen, then twice as large again. Cass used a diagonal movement on the track pad to scroll to the bottom right-hand corner of the image, and leaned back, cocked her head, squinted.

“Yep,” she said. “I am as cool as everyone says.”

She closed the window and opened another from the folder, apparently at random. A three-quarter view of Karren was treated in the same way. “Again. See?”

“See what?”

She tapped a key combination and the image popped down a level in resolution. She caused the cursor to circle around the date and time stamp in the corner. “Examine the edges of those numbers.”

I looked more closely. “I don’t get it.”

“They’re not real.”

“Not real?”

“The way date- and time-stamped numbers appear on digital photos is pretty distinctive. These look off. The edges are too sharp, don’t have the halo. Could just be the camera in question, it does vary from brand to brand, but I don’t think so. Let’s check something else.”

Another key combination, and a long thin window popped up next to the image, filled with orderly lines of text. She ran a finger down it, humming to herself.

“Aha.”

“What’s all that?”

“The EXIF data for the image. Let me check another.” She reopened the first image, and the side window filled with similar data. “Bingo. My awesomeness abounds.”

“I don’t understand what you’re showing me.”

“E-X-I-F,” she said, spelling out the letters as if to an illiterate cat. “That’s Exchangeable Image File format to you. A way of storing metadata about a picture, in the file itself. When a digital camera takes an image, it injects pieces of information into the JPEG or TIFF, where it can be accessed by any viewer application. It will typically store the aperture, shutter speed, focal length, and ISO setting—and some will even log geolocation data in there, too.” She placed the slender tip of her finger near the top of the data window. “And of course, basic, it will log the time and date when the picture was taken.”

I looked at the date next to her finger. Then at the numbers in the corner of the image itself.

They were different.

“Hang on,” I said. “The numbers on the picture say it was taken midevening on the twelfth, Tuesday. But the EXIF data says the eleventh. Which was Monday.”

“That would be my point.”

“But wait . . . wait a minute,” I said, as it dawned. “On Monday night I was out with Stephanie. All evening. From before dark. So if these were taken on Monday, then it couldn’t have been me, and she would know that.”

Cassandra tipped her hand like a seesaw. “Don’t get too excited. The EXIF data relies on the camera’s settings as much as the old-school time/date stamp would. If someone set the camera to the wrong date or time, the EXIF stamp will be wrong, too.”

“But I set the date and time correctly.”

“I’ll bet. But you can’t prove it. You could have changed it to take the pictures, then changed it back, for some fell purpose of your own. You can’t use those numbers to actually prove when the picture was taken.”

“But something’s hinky with them—because either way, the two dates should be the same. Right?”

“Yes. Someone faked the date and time onto those images to pin it to a specific day and time. Which—”

She stopped talking abruptly, mouth hanging open. Slapped herself upside the head. “Well, duh.”

“What?”

She appeared pained at her own stupidity. “What’s the word you keep seeing? Modified?”

“They modified the dates, I can see that, but—”

“No no no. Not only that, my friend. It’s not just one thing being modified, or even a bunch of little things. It’s an actual mod.”

“What the fuck is a mod?”

“Rewind. I play games, okay? Computer games, online. This has been established in prior conversation. Recall?”

“Yes.”

She looked perplexed. “You really don’t know what a mod is?”

“No.”

“Okay. In gaming terms, a mod is what it sounds like—a modification—but actually it’s more than that. It’s ontological, world changing. It’s a file or patch you deploy in a computer game that alters a player’s circumstances—or the world—in fundamental ways. It’s an old-school idea—been around since people were playing Middle Earth text-based games back in the 1960s.”

“Alters them . . . how?”

“Depends. A weapons mod might mean that a character in a fantasy medieval universe suddenly has access to unlimited arrows, or even a gun. An environmental mod could mean anything from castle walls turning rainbow colored, to there being no trees or horses or gravity. You see?”