The solution took Thomas weeks to work out, and once he did, it seemed obvious. Even so, he wasn’t at all sure that it was possible. Determined to make the attempt, he once again wrapped the note in a shell to isolate it from time and projected himself into the past.

Back in his old lab, he began looking for something he could use. The overall tidiness of the room made his search harder. Finally, he found a crumpled piece of paper in the wastebasket. Unable to interact with it directly, Thomas began casting the stasis spell. This was the most uncertain part of the solution: would he be able to cast a spell in the past? Against his expectations, it worked, and the paper was unmoored from time. Now he could pick it up easily.

The idea was an equal exchange of mass between temporal moments should prevent time from rejecting either. He had succeeded in removing the mass of the crumpled paper, so theoretically there should be a “gap” in mass that his note could now fill. He placed the note on the table in the corner, and, after a deep breath, released the stasis spell. Unlike his first attempt, the note stayed where it was. Now he had to wait for his past self to notice it.

Nearly an hour passed before his patience was rewarded. When the other Thomas saw the note, he picked it up and unfolded it. As he read, his face did not hide his surprise. Now that he had accomplished his goal, Thomas returned to his own present.

He was back in the house he had founded. There were no obvious changes. Thomas did not even remember finding and reading the note. Yet he had watched himself read it. Why did his memories not reflect that? Something had to be different. Perhaps the attack had changed, even though there were no obvious changes in his own room. The only way to be certain was to travel back and watch it again. He had visited that moment so often that he could cast the spell without thinking about it.

The scene looked just as it had every other time he had watched it. Just as the intruder entered the lab, Thomas cast a spell to stop time. He hadn’t tried before, but his success with the stasis spell gave him reason to believe it would work. When he finished casting everything was frozen. Now he could examine the attacker more closely.

As he approached the other mage, a voice startled him.

“You aren’t the only one who can wield time magic, you know.” The other mage was staring straight at him.

“How . . . ?”

“I just told you. I’m not going to repeat myself.”

“Why are you doing this?”

“Before I answer that, what are you doing?”

“I am trying to discover the motive behind this attack, as well as the identity of you and your accomplices.”

“Really? That’s all you’re trying to do? Nothing more?”

“What else would I be doing?”

“Trying to change the past, perhaps? Alter the outcome of this encounter?”

“What if I am?”

“I would have thought your master taught you better.”

“You mean the man you kill?”

“None of this happens without you. Try to remember that.”

Even though Thomas had not canceled his spell, time began moving again. The attack began to play out just as it always had. He didn’t wait for it to end. Instead, he returned to his present.

Having nothing to offset the extra mass, he left the piece from the attacker’s shirt in its stasis shell. Once he could figure out how to remove it without it disappearing from this time, the fabric might provide him with some clue about the identity of the attackers.