The Joker's attack had given Bruce a kernel of an idea and it all depended on a small chance given to him by the Justice League. It was easy to rewrite the algorithm of the virus that had invaded Gotham. The League was dependent on his knowledge for continued experiments in advancing technology and using the parameters he waited until Terry suggested they test it on the Car before actually making such a sacrifice.

He had waited until the new Batman was distracted before setting it up. He was quite aware he was throwing this small family into the unknown however if he could save them then so be it. They didn't need to take the same sacrifices he and his family had. They didn't have to take those risks and he had seen what would happen to Terry first hand.

It was insane and would probably land with him in some kind of cell within Arkham... if he was ever discovered. His heart was weaker and he was slowly dying. Gotham was already promised the direct attentions of the League if anything happened to him or Terry.

It was a small insurance that he had drawn from Clark at the time he began working from the shadows with them again. Clark suspected that he was going to do something. There was no way he could allow this child to take on the responsibilities of the Batman with his family in the dark. So, he wrote the letters. He reprogrammed the boom tube with technology only the senior members of the League had ever known existed and he packed away all the things he knew Terry was going to need. He then sent men to take the McGinnis family from their home while Terry was out patrolling. He waited until his most junior partner came back to the cave before sending him out to test the Car's new schematics, never knowing he carried his own family in the undercarriage of the very car that would never return home. How could it?

Bruce Wayne had sacrificed the materials that made the car what it was to safely carry away what he considered his final duty. To protect his unknowing family from his legacy.

That's what Batman did, right, protect the innocent no matter the cost to himself?

Bruce hadn't been aware he'd been talking aloud to himself as Dick and Barbara watched him from behind a secret mirror. Oblivious as Bruce was to the rest of the world, neither of the Batman's former partners knew just what to make of his descent into... this.

Dementia. When Bruce's doctors had contacted him with the news he'd been horrified at what it meant. The onset had been subtle enough that they hadn't caught until the man had done something he normally wouldn't have considered doing. He'd kidnapped a family and sent them into the multiverse to protect them from Batman, the original Dark Knight. According to the whispers and mumbled statements under his breath, Bruce knew some of what was happening around him.