Jodie Foster stars in this uneven but good-looking approximation of the popular book, made by husband and wife team Mark Levin and Jennifer Blackett. Foster tries to prove she can do comedy as Alexandra Rover, the faint-hearted and reclusive author whom young Nim summons up to save her island in the sun.

The comedy lies in the fact that the writer is the reverse of what Nim (young Abigail Breslin of Little Miss Sunshine fame) expects. She imagines Alex Rover, the fictional adventurer and escapologist, whose book she has read. The real-life Alexandra is terrified of spiders and won’t go out of her Manhattan fastness to collect her letters if they are not placed within a foot of the front door.

No use at all, in fact, when Nim’s island gets threatened by interlopers intent on ruining it with a tourist hotel. Added to that, her father (Gerard Butler, oddly doubling as the fictional Alex Rover) gets shipwrecked in a storm and Nim is left alone on the island, which is apparently broadband enabled, to fend for herself.

She only has three friends and they can’t do too much for her since they are a sealion called Selkie, who is as sloppily affectionate as any labrador, a bearded dragon called Fred, who is equally in love with her, and a slightly more independently minded pelican called Galileo.

But it all works out by the end, even if the plot may only be wholly understood by kids with rather more imagination than their parents.