ipoophere:

Modern AU where everything is digitalized and stored in an enormous computer system that practically runs the whole city. The system is protected by 3 firewalls, each customized by experts to ensure that all internal information never gets out. 

HOWEVER, an unknown computer virus has managed to break through the first firewall, creating havoc within the first branch of the system, causing information blackouts and disruption to the city’s network. The virus(es) are nicknamed 'Titans' and they eat up whatever is in the system, seemingly unstoppable by regular virus software. That is until a new program is developed, in which users are integrated into the digital surface, where they can deal with the Titans head on. 

Even with a specialized team on the job, the viruses just keep on coming, and some of them seem smarter than just ordinary viruses. Could they be user-controlled? And just why are they trying to break the firewalls down? Are the firewalls really just keeping information from getting out— Or are they keeping information from getting in?

The questions are endless and when teen hacker, Eren Jaeger’s program is corrupted by the virus, he finds that his mutated software could possibly provide the answers that they’re looking for.