Baltimore 1962 and America is in the grip of Cold War paranoia. In the hidden high-security government laboratory where she works as a cleaner, lonely, mute Elisa lives a mundane life. Her only friends are an older gay male neighbour Giles and her co-worker Zelda. But everything will change when Elisa stumbles across a classified experiment in one of the labs. The authorities want to use this unusual creature shipped in from Latin America in the war against the USSR but Elisa sees a lonely being in need of friendship and love.