Reviewed - The Lake House: Advance publicity for this stunning romantic drama - stunning in the sense that shards of it could be fired into charging rhinos to stupefy them into unconsciousness - has left punters deeply puzzled.

The summaries of the plot appearing in previews of summer blockbusters have generally gone something like this: Keanu Reeves and Sandra Bullock, the first of whom lives in 2004, the second in 2006, exchange letters through a magical mailbox and, charmed by one another's prose, fall deeply in love.

I beg your pardon? The last time Bullock and Reeves shared a screen the plot could be encapsulated in one terse sentence: if the bus goes under 50 mph it blows up. By contrast, you could write a 10,000-word treatise on The Lake House and average readers would still find themselves profoundly puzzled.

The scenario makes a tiny bit more sense when you actually see the film. Listen carefully. Reeves, an architect estranged from his grumpy father (the gratifyingly eternal Christopher Plummer), moves into a beautiful lake house just outside Chicago. Before unpacking his things, he discovers a letter from the "previous" tenant (henceforth imagine that all temporally related words in this review are enclosed by inverted commas) asking him to forward her mail to a location in the city. But the address is at an apartment complex yet to be built. Stranger still, the mysterious correspondent apologises for a series of dog's footprints that are nowhere to be seen until, as Keanu is folding away the note, a mutt runs through a puddle of paint at the house's entrance. The letter, you see, is from the future.

I suppose it is foolish to be surprised at anything in a film that asks us to believe Keanu Reeves might be an architect. But barely a second goes by without some new conundrum troubling the viewer. Keanu and Sandra have just happened across a phenomenon that undermines several millennia's worth of thinking about time and space, yet, upon realising the mailbox's powers, their mildly bemused aspect suggests two scrabble players saddled with a few too many consonants.

What gives? As events progress, the questions keep piling up. If he does that thing in the past why doesn't this consequence follow in the future? What would happen if you put some small animal in the mailbox? Hell, what would happen if you somehow crammed your whole head into it? Hang on. An architect?

Of course, the fact that we are distracted enough to ask these questions demonstrates that there is something fatally awry with The Lake House. The two leads are perfectly charming and Alejandro Agretsi, the Argentinean director of 2002's sweet Valentín, scatters some nice split-screens and arty wipes about the place. But, aside from the most astonishingly unlikely event the universe has seen since its creation, nothing much happens in the picture. The lovers sit writing letters. Time passes. They write some more letters. Leaves fall. And so on.

Oh, for Dennis Hopper, a bus and a bomb.