What if Hitler survived World War II? It's the stuff of novels, movies and TV shows - and reality, if one former CIA agent is to be believed.
In a new TV Hunting Hitler screening on The History Channel, Bob Baer claims the Nazi dictator faked his death and fled to South America - by submarine.
Mr Baer says recently declassified documents from the FBI and British intelligence sources prove Hitler didn't kill himself in a suicide pact with wife Eva Braun, as is commonly accepted by historians.
"What we are doing is re-examining history, history that we thought was settled that Hitler died in the bunker but the deeper we get into it, it's clear to me we don't have any facts for it," Mr Baer told UK media.
There's evidence, he claims, of a secret exit from Hitler's bunker. After sneaking out this way, it's alleged the fascist demagogue jumped on a plane, flew to Denmark, got on a second plane bound for Tenerife in the Canary Islands, where he boarded a submarine bound for Argentina.
The intention was apparently for Hitler to rise again, as leader of the Fourth Reich. If he made it, he clearly failed.
It's a historical fact many Nazis sought refuge in South America. Many leaders of the time, such as Juan Peron, had fascist sympathies, in addition to seeking the Germans' military and technical expertise. The Allies largely turned a blind eye - they'd rather German expertise end up in in places like Chile and Argentina than in Communist countries.
Adolf Eichmann - who facilitated the Holocaust - was found by Israeli Mossad agents in Argentina in 1960, extradited, tried and hanged.
"No one expects to find Hitler and there are no first-hand witnesses alive that are credible who actually saw him [in South America]," Mr Baer told the Sunday Express.
"On the other hand, there are Nazi communities in Argentina who just refuse to talk."
Mr Baer, a former CIA agent posted to the Middle East, has previously questioned the official story behind the 9/11 attacks, but rejects claims it was an inside job, saying the CIA couldn't pull it off.