Who?

An American researcher suffers devastating injuries in a car accident near the East German border and is taken captive by East German forces. To save his life, they fit him with advanced metal implants. When he returns to the United States, doubts arise about his true identity, leaving everyone uncertain if he is indeed the same man. An intelligence officer is tasked with uncovering the truth behind the enigmatic figure behind the "mask" and determining whether he can be trusted.