London shines in all its glory - its architecture, its iconic river and the impressive edifice of the Thames Barrier gleaming in the sunlight. Meanwhile, in Scotland, a storm of hurricane proportions crashes into the coast, devastating the sleepy town of Wick and sending mountainous tides towards London.
Rob Morrison, head of Atlantis Engineering, is called to the Thames Barrier for a maintenance check. His ex-wife, Sam, (Jessalyn Gilsig) the Barrier’s Director of Operations, is the last person he wants to see. Meanwhile his estranged father, engineering genius Leonard Morrison, desperately warns about the impending deluge. Together, they must all put aside their differences to save London from certain destruction.