"...a Comedy Tonight!!"Edit
The Joker hacks into the computers in Gotham City, including emergency services and government computers and sets the city into disarray, with power outages and fires everywhere. He has sent a tape to the Mayor, which he decides to withhold from the public in order to save face. This leaves it up to Commissioner Gordon to deal with it all. Gordon is forced to confer with Robin, because Batman is out of town.
The next day, the Joker hacks into the Jumbotron at Gotham Stadium during the Hammer Bowl. He demands one billion dollars as ransom to set the city back in order, but with the catch that it must be delivered by Batman personally. Alfred realizes that the Joker has called Tim's bluff, and is well aware that Batman isn't in the city.
Later, Tim plays Warlocks and Warriors with his friends as the Dungeon Master. When faced with the challenge of creating a scenario for his friends to play out, Tim sets up something similar to what is actually happening in Gotham. The king is away, and a mad wizard has taken over the country, leaving only the king's son to deal with it. Ives recommends that the prince follow the flow of the wizard's magic to track him down. This causes Tim to realize that he should follow the Joker's trail over the internet by hacking, and leaves the game without explanation.
Tim attempts to use the Batcave's two Crays to hack his way into the Joker's mainframe. After hours of digging his way through the server's shell, Tim realizes that the Joker has actually used the connection Tim established to hack into the Crays themselves. Desperately, Tim cuts the power before the Joker can get any information from them.
The Joker causes even more havoc for Gotham, such that the mayor asks to have the city declared a disaster area. Tim decides to stop reacting, and do some real detective work. He sneaks into the kidnapped Dr. Osgood Pellinger's house seeking clues. Eventually, he comes across a shoebox flield with photos and memorabilia of Pellinger's childhood dog. Meanwhile, the Joker delivers his demands to the mayor's office, and a frustrated Commissioner Gordon warns Robin against facing the Joker alone.