Wonder Woman and Superman have to rescue Joker from Mongul, whilst Batman and Flash try to stop a massive laughing gas bomb hidden away in Gotham.

Joker frees Luthor with a mother box and forces him to spend the day together, hopping all over the world, with the Justice League hot on their trail trying to catch up.

When the Joker traps Batman, the Justice League allows Riddler to help them find him.

When Booster Gold starts to secretly give tours of the Watchtower to make some extra cash, he inadvertently brings in at least one super-villain disguised as a tourist.