Prince Farnese is condemned to death and his wife makes an impassioned appeal to the Pope for his life. Moved by her eloquence and anguish, he cannot refuse her request, and gives her an order to the prison warden to deliver the prince to her at the stroke of two of the castle clock. After she has departed he issues orders to have the execution take place at the stroke of one. The chamberlain betrays this fact to the princess and her page mounts to the high steeple and tampers with the clock so it strikes twice when it should strike once. The ruse is successful and the prince escapes. When Sixtus learns how he has been outwitted, he is very wroth, but before he can take steps to recapture the prince he passes away, the end coming in a sensational scene, as he is surrounded on his throne by the cardinals and ambassadors.
—Moving Picture World synopsis