Dressed in their brashest and best they dined well, if a trifle expensively considering another car was on the shopping list, at a bistro on the waterfront. By nine-thirty they had fronted up to the nightclub, forked out for membership and entrance, and ascended the two flights of stairs. The large, dim space contained glittering reflections of four mirror-balls, a small dance floor, Hard Rock music blasting from a dozen speakers, assorted tables and chairs, and a bar. A couple of hunky waiters