"It's all your fault, you damned parasite! Now look what happened—we're completely trapped in here and can't get out!!!" Barry gritted his teeth and said in his mind with the fiercest tone he could manage.
At that moment, he was in a dark passageway. The walls bore worn patterns, and the ground was extremely damp. Every step produced a tap-tap-tap that echoed through the silent maze, making it all the more chilling.
Barry hugged his arms as he slowly walked forward. "I told you I should've taken that chance to find somewhere to climb up. Now the way overhead is blocked too. Which way are we supposed to go?"
"Why are you such a coward?!" Doctor Strange said coldly in his mind. "How can you gain power without paying a price?"
"I didn't come here to gain power." Barry spoke righteously. "There's an extremely dangerous energy core beneath Gotham City. I suspect Gotham's darkness is inseparably connected to it. If someone really is up to something, I have to know what they're trying to do."
"Got it, little hero. Turn left now. I can sense the traces of energy becoming denser at the intersection to the left. I think we're almost there."
After separating from Harley and Little Bruce, Barry had not been idle either. He wanted to find this universe's Batman and have Batman figure out a way to send him back, preferably while driving the strange voice out of his head. Barry was nearly being driven insane by the evil plans it muttered about every day.
But just then, Doctor Strange showed Barry the flow of magic from his perspective. For certain reasons, Doctor Strange, who possessed the Darkhold, was particularly sensitive to powers tied to concepts such as darkness. Even after changing universes, he was like a