Barry's mind raced. He needed time alone with The Flash from another universe. Making up his thesis was a pretty good excuse.
That professor would surely realize that time within the Speed Force was infinite. As long as he put on a worried expression, the professor would definitely let him go into the Speed Force with The Flash to make up his thesis.
And precisely because time in the Speed Force was infinite, the professor would never know if the two of them did something else.
Barry did not think there was any need to let the current Professor Schiller know about the future. Even if he knew, it would not be of much use.
Even a few years ago, Krypton had already been destroyed. If there was some mastermind behind it, the plan had surely already been carried out. Someone as powerful as Hal was not someone who could be stopped through prevention. There was no need to create more worry.
And if changing the timeline caused Hal to arrive earlier, before the Justice League had established its defenses or built its magical defense network, the situation would only become worse.
So, although the image of Hal's heart nearly being torn out kept replaying before his eyes, he still answered Schiller's questions with a joking manner and a hint of nervousness.
Finally, he entered the Speed Force with The Flash from the other universe.
His expression immediately fell. The Flash patted him on the shoulder and said, "You don't have to look so upset. It's just a thesis, right? How much have you written? Let me take a look..."
Barry flung his hand away, stood there taking several deep breaths, then forced a smile at The Flash. "Sorry. My Speed Force is pretty dangerous. You'd better not touch me."