Robin #10 Zero Hour
Robin is pursuing a jewel thief who is known as the Weasel due to his talent for making a getaway. He is rather surprised to find himself assisted by ... Robin, as in Dick Grayson, brought to the present either from the past or an alternate timeline. The two Robins work together, chasing the Weasel through Gotham Aquarium and having a close encounter with sharks and a killer whale. They then see him fall into a tank of piranha and call the police to get his skeleton out. The current Robin then has a flash of brilliance and the two of them head back inside, finding the crook - wringing wet - hiding in a cupboard. He had evidently planned his escape route long ago, as the tank he 'accidentally' fell into contains a species of piranha which does not indulge in eating flesh. However, as they hand him over to the police, first Dick and then everything else fades from existence...