CIA officer Carrie Mathison is tops in her field despite being bipolar, which makes her volatile and unpredictable. With the help of her long-time mentor Saul Berenson, Carrie fearlessly risks everything, including her personal well-being and even sanity, at every turn.

After a plot to kill the president of the USA an agent with lost memories tries to recover his life and memories. Others use him to cover up some dirty business involving high ranking officials from the CIA and the White House.

A murder is investigated by both sides of the line, cops and criminals, using opposing methods. But the real line is the morality within each person and how far they will go before they cross it.