Detective 1,000,000 (Nov. 98) is part of the DC One Million crossover series, which sees heroes from the 853rd century trade places with theirpresent day counterparts, but the evil sentient sun mess with the plans, releasing the Hourman virus. Nightwing tries to explain it to Robin, who followed that as well as you did. Chuck Dixon scripts, with Greg Land on pencils and Drew Geraci on inks.
That’s Batman One Million (as it’s easiest to call him), in the Batcave to the consternation of Alfred. He modifies the Bat-computer with his future tech, in order to see if there is a way to deprogram the nanite-based Hourman virus.
The virus drives people into paranoid mania, and Firefly takes advantage of this to lead people into burning their own homes.
The future Batman confesses to Alfred that even with his modifications, no computer with the present technology will be able to “cure” the Hourman virus.
He proves more successful at taking down Firefly, and his suit’s ability to fly makes it even easier.
In the end, he realizes that in order to defeat the future super computer sentient sun Solaris, they will have to create it in the present.
The story continues in JLA 1,000,000.