This time, Frank and his girlfriend Sarah are unwillingly dragged into an attempt to track down a uniquely dangerous nuclear weapon that was smuggled into Russia during the Cold War. Along the way, they encounter the bomb's inventor, who has been kept drugged-up in a prison for the criminally insane for 32 years; Frank's old flame Katya, a former Soviet spy who delights in winding up Sarah; and Han Cho Bai, the younger generation's deadliest assassin, who has been tasked with killing the ageing agents.
With the comedy more to the fore in this outing, the wisecracking veteran thesps' enjoyment is infectious.