John Huston's Key Largo shares crucial similarities and differences with Archie Mayo's The Petrified Forest, also starring Humphrey Bogart but made 12 years earlier. The two plots are similar -- a group of people held hostage in a remote locale by a gangster on the run -- but the differences between the two movies, and Bogart's roles in them, reflect changes in the world and in perceptions of evil and how to deal with it. Where The Petrified Forest was steeped in romantic notions of self-sacrifice, rationalizing the loss of life in World War I, Key Largo implicitly questioned the right of any moral person to withdraw from the responsibility of taking moral action -- and it even questioned the wisdom of self-sacrifice. The Petrified Forest's dreamy poet (Leslie Howard) nobly sacrifices himself to see the capture of the deadly sociopath played by Bogart. In Key Largo, Bogart plays embittered, disillusioned war veteran Frank McCloud, who starts the film with nothing to live for and discovers, in the course of fighting and killing old-time gangster Johnny Rocco (Edward G. Robinson), that there is a reason to remain engaged with the world and with his fellow human beings. The difference between the two movies was the intercession of World War II, in which society encountered the most monumental evil on as large a scale as was imaginable. Made in the wake of the war, with the Cold War and the Red Scare just getting rolling, Key Largo was almost a call to arms to any decent people watching that they were too important to withdraw from battlefields old or new, and that there were still battles to be fought that were worth fighting, as well as winning.