National Treasure starts out with a vast implausibility: A sailing ship frozen in arctic ice for 200 years, with no explanation of how it could survive intact the griding and crushing of moving ice that have left better vessels crushed into oblivion.

Nicholas Cage plays Ben Gates, the latest scion of a family cursed since the Revolution with the knowledge that somewhere in the US the founding fathers have hidden a treasure amassed (or stolen) by the Knights Templar. The Gates men have been searching for the treasure ever since, and Ben has discovered that a clue is in the boat.

What follows is a delightful romp through improbability after improbability. Ben is forced to steal the Declaration of Independence in order to keep it from being stolen by his former partner turned badguy Ian Howe, played by Sean Bean. Helping Ben is Justin Bartha as computer wiz and comic-relief sidekick Riley and Diane Kruger as National Archive Conservator Abagail Chase. After the theaft of the Declaration, Harvey Keitel joins the action in a too-small role as FBI Special Agent Sadusky, and Jon Voight comes on board as Ben’s father, who believes that the treasure is a fake.

Ian and Sadusky both chase Ben & company through various car chases, Independence Hall, Trinity Church and catecombs beneath Wall Street, while Ben chases clues that come from objects ranging from a Meershaum pipe and special glasses constructed by Ben Franklin to a $100 bill. The characters are, of course able to determine the true meaning of extremely obtuse clues without even breaking into a sweat.

Improbable, yes, but prepare to suspend your disbelief. Although instantly forgettable, National Treasure makes a pleasant holiday-season (almost) diversion.

Mom’s take: