Vacation - spiritual sequel to National Lampoon's Vacation

Ed Helms and Christina Applegate, well-known comedy actors posing in a fake marriage, were trying to protect their two fake sons from a fake tsunami.

The quartet, joined by Charlie Day as a volatile fake river-rafting guide, were in a boat one morning last autumn at a small water park. They were contemplating how they'd managed to get themselves into this vacation situation and, more importantly, how they'd get themselves out.

A portable geyser doused them with water. A raft rocked angrily as burly men puled on wires to tame it. Oars and other navigation devices were as absent as a Rand McNally map at a Google convention.

"You're our only hope," Helms wailed to Day. A moment later, a director yelled "cut", and the group emerged from the boat - life-jacketed, wet and in Applegate's case, visibly queasy - to join crew members on dry land. "Just like being on a real vacation," Helms said, flashing his square grin, as he bounded over to a set of monitors in socks and slippers, waving aside a dry sweatshirt the way a tennis player declines a new ball.

The actors were inhabiting the Griswolds, a name with plenty of cinematic currency thanks to the landmark 1983 comedy National Lampoon's Vacation; it featured John Hughes as writer, Harold Ramis as director and Chevy Chase as star. A subversive and innuendo-laden movie that sent up the nuclear-family entertainments of the 1950s, Vacation became a huge hit upon release, then spawned four sequels and countless imitators. One is hard-pressed to think of a contemporary family-centric comedy - RV, Are We There Yet? and countless others - that doesn't have a little Griswoldian DNA in it.