

He spent two weeks testing it carefully.
The first thing he established was that he could not trigger it on purpose. He tried. He sat in his room and concentrated and willed the world to go back ten seconds and nothing happened. He tried while walking, while eating, while doing homework. Nothing. The power did not respond to wanting.
It responded to something else.
The second time it activated was when his little sister almost fell off the climbing frame in the park. The click in his chest. The world going back. His sister unhurt, puzzled by his sudden shout of warning, but unhurt.
The third time was when a cyclist almost rode into an elderly man who had stepped off the kerb without looking.
The fourth time was different. He was in the supermarket with his mother and he dropped a jar of pasta sauce and it fell toward the hard floor. He felt the beginning of the click.
And then it stopped. Nothing happened. The jar hit the floor and shattered.
His mother sighed. A shop assistant came with a mop. Eli stood in the middle of the mess and understood something important.
The power only activated for people. Not objects. Not inconveniences. Not embarrassments. Only when a person was about to be hurt.
He wrote this in his notebook that night, the plain grey one he had started keeping specifically for observations about the power. The notebook was hidden under his mattress, which was not the most original hiding place but was better than nothing.
He wrote: It is not mine to control. It decides when it is needed. I am just the one it happens through.
He stared at this for a while.
Then he wrote: Ten seconds is not very long. You have to use them well.
Over the following weeks he started to understand the geography of the ten seconds. He thought of it as geography because it had edges and limits the way a map does, places where it worked and places where it did not. Ten seconds was enough to shout a warning. Enough to pull someone back from a kerb. Enough to redirect attention, to change a small thing that prevented a larger thing. Ten seconds was not enough to move a car or stop a serious accident from above. It was useful in very specific circumstances and not useful at all in others.
He also noticed that he was tired afterward. Not dramatically tired, not falling-asleep tired, but a low steady tiredness that sat behind his eyes for an hour or so after each event. As if the rewind cost something real, something that came out of him rather than out of nowhere. As if the rewind cost something. As if time was not free to move backward and the cost came out of him.
He added this to the notebook. He was building, slowly, a complete picture of what he had. The picture was not flattering in the way that superpowers in films were flattering. It was smaller and more particular and came with a cost. But it was his and he was beginning to understand it.
He did not think of himself as a superhero. The word felt too large and too costumed for what was actually happening, which was a quiet, private, slightly exhausting thing that happened when other people were about to have a bad day.
He thought of himself as someone who occasionally got ten seconds back.
That felt closer to the truth.