The Joker:  There are only two ways to get out of there . _ One _ : I let you out . And two : you jump fifty feet straight up !
Batman: You still intend to free us if we can stay afloat for an hour ?
The Joker: Oh , dear me ! Surely you do n't think I 'd joke about such a serious matter as that , do you ? Time to start filling the tank !
Batman: But ... that 's gas !
The Joker: I do believe you 're right ! But then , who said anything about water ?
Robin: But you ca n't float in gas !
The Joker: No , but you can drown in it !