The next couple of years, their lives were dedicated to preparing the cave and to research. Bruce spend a lot of days reading and studying about psychology and criminal investigation, helped by advanced teaching methods from his computer friend. Alfred decided to protect the boy as good as he could by sharing his own, hands on experience, from his time in the army and at Scotland Yard. He even showed Bruce some of his old case files, as a last attempt to scare the boy off. He quickly learned, however, that this wouldn't work, as the boy worked through them and even solved most of them. The boy was fast, faster than anyone else Alfred had ever met. He could read books in minutes and think just as quickly.
Asides from developing his brain, Bruce spend lots of time developing the powers he already had. They brought different targets in different materials down, to test the power and train the accuracy of his laser eyes. He really seemed to grow, in controlling the strength and accuracy of his beams.
His hearing, however, was another story. Alfred would see him spend hours just focusing on his hearing, trying to hear beyond the bats. But every time he would end up holding his hands over his ears and screaming in frustration. He regularly punched a hole into the bedrock, cursing the bats out loud when he couldn't quite bottle up his frustration. These were the times Alfred was really worried about the boy and what he might do. These, and the times Alfred would wake up in the middle of the night when he heard Bruce scream. He would walk into young Bruce's bedroom and find the boy trashing in his bed, ripping his sheets apart or punching straight through his mattress. The first couple of times Alfred had moved in to comfort the boy, but he was thrown back into the wall once, and could just evade being burned by Bruce's lasers another time. After that, Bruce decided to sleep in the cave. There would be less damage in there.
One night, Alfred came down to find young Bruce lying unconscious on the floor with a green rock next to him. He dropped the tray with food to the floor, and ran down the stairs. "Master Bruce, Master Bruce!" He yelled. "Brainiac, what happened?" The computer screen they installed just flickered and showed some Kryptonian gibberish. When Alfred reached them he did the only thing he could think of and kicked away the only unknown thing in the cave, the glowing green rock. When it had rolled far enough Bruce jumped up as he pulled in a deep breath and Brainiac flipped back online. "What the bloody hell happened? What was that thing?"
Bruce was still catching his breath, so Alfred turned to the computer. "It was a piece of Krypton." The computer stated. "We found the specific signature of Kryptonian material using the Waynetech satellites. Bruce decided to try and learn more about his home. The effects were... not as expected. This piece of Krypton seems to have been radioactive. But only to other Kryptonian life forms, as the evidence shows."
"So that's why it influenced the two of you?" Alfred asked.
"Yes, it seems to me that the radiation shorted out the living circuits in the ship. That's why even I couldn't call for help. I already put a fail safe in place for when this would happen again." The computer blandly stated.
By this time Bruce had caught his breath. "Thanks, Brainiac. I think it wouldn't be a bad idea to plate him with lead as well, Alfred." Bruce coughed.
"I'll take care of that personally, master Bruce." Alfred answered. "Now stay here as I take care of this blasted piece of Kryptonian plutonium."
Bruce smiled. "Kryptonium" he said with a musing tone in his voice "I like the sound of it."
Alfred shook his head, got up and grabbed the piece of rock. "I must have some sort of lead laced box somewhere upstairs." He walked up and by the time he came back down Bruce looked a lot better. "By the way master Bruce." Alfred remarked. "What Brainiac said made me think. He said THIS piece. Are there more pieces out there?"
Bruce nodded. "Show him Brainiac."
A world map appeared on the screen. Several places, all over the map were pinned with green markers. "These are all the places we found this specific type of ... kryptonium, as master Bruce named it."
"This specific type?" Alfred shook his head with confusion. "Are there more?"
Markers in a couple of other colors popped up. "There are some, slightly different, types out there. Each of them emits a different kind of radiation and might have a different effect on young Bruce."
"It seems like we finally found a weakness in my Kryptonian body." Bruce said with a smile. "Let the scientists in Wayne Industries perform all the tests they can on it. I think I will do some traveling."
"Master Bruce?" Both Brainiac and Alfred asked at the same time.
"I need to develop my powers more. I can't do that in this cave. I must see the world and learn about my limits and weaknesses in real life situations. I need to gather real experience." Bruce said with a voice filled with determination.
Alfred knew there was nothing to do or say that would stop the boy. "Then let me go with you, master Bruce."
"No, Alfred." Bruce shook his head. "I need to do this alone. I'll take a communicator with me to stay in touch with Brainiac and you for information."
"Very well then, master Bruce. I'll have the Jet prepared for tomorrow." Bruce did not react to that, but the next day when Alfred went to wake him up, he found the bed unslept and the cave empty. Brainiac relayed him the message that young Bruce had set off on foot to train his already overpowered muscles and to find their limits.