But an accident at the Thames Barrier, combined with a tidal surge and a dramatic thunderstorm - and suddenly his trip turns into something totally different as the Barrier is breached and London is flooded. But as Ben tries to get across London to meet his mother, little does he know that two terro...

But an accident at the Thames Barrier, combined with a tidal surge and a dramatic thunderstorm - and suddenly his trip turns into something totally different as the Barrier is breached and London is flooded. But as Ben tries to get across London to meet his mother, little does he know that two terrorists have a similar rendezvous .