People with pacemakers die without cause; lifeless pigeons fall into Trafalgar Square; the Colosseum implodes; the Golden Gate Bridge melts. A normal day in a crazy world. But this isn't the work of your latest terrorist cell or rogue regime. It's the earth's electromagnetic field, thrown into possibly apocalypic turmoil by the stagnation of the planet's liquid centre. Cue every golden boy geophysicist, super-hacker, spurned desert inventor, egocentric pop scientist and dubious general on the block, add a laser drill attached to a giant steel worm and head for the core with a nuclear payload to kickstart some magma. So far, so high concept, but this is not a movie so much as an acceleration, through narrative, character, visuals and even suspense. Think Fantastic Voyage crossed with PlayStation. The effects here are extraordinary, the cast is calibre, if low wattage, but performances burn up once the crust is breached, and the script is laugh-aloud ludicrous.