Back in 1985, the fall of the Soviet Union was not yet assured, but the wheels of progress were already moving within the Soviet Bloc. Glasnost, the Soviet policy of openness and transparency that, in many ways, helped usher in the collapse of the Soviet Union in favor of modern-day Russia was still a year away, but Mikhail Gorbachev had already begun establishing himself as a different sort of leader than his predecessors. Perhaps that’s why American President Ronald Reagan felt comfortable enough with the man to pose an interesting and enigmatic question during the 1985 Geneva Summit.

During the high-level diplomatic talks, Reagan and Gorbachev took a short break from their ongoing negotiations to go for a walk, accompanied only by their private interpreters. The two leaders, each in control of the most powerful militaries on the globe at the time and actively working to prevent a nuclear war that could mean the end of all mankind, walked and talked in secrecy, not sharing the details of the conversation with the world for decades to come. It wasn’t until 2009, in fact, that the subject of their short conversation finally came to light.

It would seem that in the midst of those high-level talks, Reagan had a different threat on his mind — one that was even more significant than that posed by the Soviet stockpile of nuclear weapons. That threat, Gorbachev would soon learn, was so unusual, it was downright out of this world.

During an interview with Charlie Rose in 2009, Reagan’s Secretary of State, George Shultz was asked what the two leaders discussed as they walked and talked in private, but Shultz was interrupted.