"We understand this political climate has turned your world upside down," the 1950s TV-ad voice- over tells you. "Underground shelter is your best defense against radioactive fallout." Cue perky music, tap dancing twins, and a ballerina that bakes the perfect croissant. Welcome to your new luxury home - buried 26 feet below. Complete with mini-golf course, dance floor, swimming pool, two jacuzzis, and a thoroughly modern mermaid. "This is reality." That is, until the nuclear siren rings.