When Edward Snowden first reached out to journalist Glenn Greenwald, Greenwald ignored his emails.
So Snowden turned to documentary filmmaker Laura Poitras.
Some of their exchange reads like a spy thriller.
For example, Snowden warned Poitras about creating a password that would be nearly impossible to hack: "Assume that your adversary is capable of a trillion guesses per second," he wrote her.
Little did she know that that first encrypted email from him would lead to one of the biggest exposé of the US government and may well define the rest of her life.
Journalist Peter Maass recently met with Laura Poitras at the home of journalist Glenn Greenwald in Brazil.
Maass profiles Poitras for The New York Times Magazine.