In 1999 several billion internationally are invested in counter measures to combat the much anticipated, widely dreaded world-wide Y2K computer virus.

Amidst these counter measures several banks in New York and London take the daring precaution of secretly stashing several billion in cash in armored cars in secret locations around the cities in anticipation of their computers collapsing at midnight on New Year's Eve.
When the virus doesn't materialize and the armored vans are recalled the next day all but one of them returns. Along with the two guards assigned to babysit the 600,000,000, van № 1989 has vanished.
The crime is never solved.
Eighteen years later, when the body of one of the guards is dredged out of the Thames the case is reopened.
Inspector Harold Morrissey of the London Metropolitan Police Service and NYPD homicide detective Frank Mahone, accidently thrown into the mix via a U.S.-U.K. exchange program, are tasked with finding out what happened to the armored car and the two guards.
What appears to be a standard murder-grand larceny case is even more complicated when they find the van in a different location a week later.
With the all money still in it.
Technology is not inherently evil. But some men are