SUDDENLY is a great example of a film that is exceptionally simple but it manages to pack a mighty wallop. I noticed one reviewer questioned why Sinatra made this film after his success (and an Oscar) in FROM HERE TO ETERNITY, but I thought it was a wonderful showcase for his talents--giving him a chance to act without all the props and distractions you'd find in most films.
The film is set in the town of Suddenly. Unknown to most of the town is that the President's train will be stopping in town today. Secret service agents have arrived in town to make sure the coast is clear. While this is all standard procedure, what they don't know is that a team of three hoods HAVE come to town to kill the man. Frank Sinatra and his two lesser hoods have staked out a home overlooking the train station and have introduced themselves to the family as FBI agents. Their real purpose is unknown until one of the agents arrives at the home with the Sheriff. After a brief gun battle, the Sheriff is wounded and the agent is dead. Now, the gang holds the family hostage until the President's train stops...and they kill him with a high-powered rifle.
Despite a very, very simple plot and a relatively low budget, the film manages to do a lot thanks to exceptional writing and acting. Frank Sinatra's character is complex and interesting. Sterling Hayden, as usual, is very solid and tough. The rest are also very good--not a bum performance among them.
In many ways, the film is similar to the exceptional Bogart film, THE DESPERATE HOURS (which is also about a family being held hostage by a gang) as well as the real-life killing of John Kennedy in 1963. While it is a myth that Sinatra had SUDDENLY withdrawn from circulation following this assassination, it is chilling how similar this film was with the murder by Oswald.
Overall, a very tight and suspenseful film from start to finish. It sure gives a great "bang for the buck". Exceptional throughout.