

Go back in time and do something to prevent Vasily Aleksandrovich Arkhipov from becoming the Executive Officer on the B-59 Soviet nuclear sub in October 1962. He’s the guy who talked the Captain and the Political Officer out of launching the nukes when they thought they were being attacked by the US Navy during the Cuban Missile Crisis. His persuasiveness is generally considered to have avoided WWIII from starting then.
17a. Reject prompt to set up a pass key.