Tommy Lee Jones plays the emergency chief attempting to save Los Angeles from molten lava in this taut, effects-laden disaster movie. Director Mick Jackson uses the simple suspense device of cross-cutting as the cast members go about their daily activities with magma bubbling menacingly just under LA's threatened streets. The digital special effects come into their own when the city is awash with rivers of fire and the urban destruction goes into overdrive. The result is a gripping and spectacular action fantasy in which MacArthur Park does indeed melt in the dark.

An earthquake shatters a peaceful Los Angeles morning and opens a fissure deep into the earth, causing lava to start bubbling up. As a volcano begins forming in the La Brea Tar Pits, the director of the city's emergency management service, working with a geologist, must then use every resource in the city to try and stop the volcano from consuming LA.