Xu Sanshi Called the Tree a Bastard, Ye Yinzhu: The Tree Decides Which Way the Lock Turns

"Yes," Huo Yuhao said. "This was what Otto proved. History can be altered by actions in the present. But whoever alters history must also make himself part of that alteration. He did it. And he vanished. In the end, the history he altered still returned to where it had been. Only now, it had a crack that only observers could see."

As his words fell, the Light Screen did not dim. As though it had finally been waiting for something to be laid bare, an exceedingly faint layer of patterns suddenly surfaced over the image that had closed back up. Those patterns spread from beneath the execution platform five hundred years ago, like the Tree's roots, or countless threads drawn impossibly thin, piercing through time, layer after layer, all the way to the instant Otto burned.

"That crack is widening," the Dragon Prince said quietly. "No. It isn't widening. It's... becoming visible."

"Because resonance itself is a signal." Huo Yuhao's pupils contracted slightly, his gaze locked on those patterns. "We only saw synchronization earlier. It never occurred to us that this synchronization wasn't a coincidence. It was the Imaginary Tree 'permitting' it." He paused, his voice dropping. "Permitting a rewrite to happen."

"Permitting it?" Xiao Xiao abruptly raised her head. "Then why did the Tree change the altered history back? If it permitted it, why did Kallen still end up..."

"Because permission isn't a promise," Tang San said. "What the Tree permitted was for the act of 'rewriting' to be proposed. It allowed that variable to appear, allowed resonance to occur, allowed an entirely new world line to be opened. But it never guaranteed that the world line would grow the way Otto wanted. It gave him a chance. But that chance itself came with conditions."

"What conditions?" A'Dai asked.