Sort of Looking for Gina

Johnny is fascinated by a woman he's met, Gina. But whenever he meets her she disappears when he's not looking. At the same time some of the misfits believe to have seen a monster in the sewer system, so all of them go down again to investigate. They discover a young boy who's become unconscious due to supposedly bad air. Also at the same time a party is being planned for the opening of an exhibition of valuable relics from the Titanic at the museum. It turns out that Gina is working together with a group of criminals, who were planning on placing a bomb in the sewer ...