A tight, quick little noir that Hollywood seemed to make so effortlessly in the 40s and 50s. Sinatra gives a very good performance as the unhinged, yet somehow still charismatic, psychopath. Solid noir and interesting if for no other reason than to see Sinatra playing the villain.
Generic setup done exceptionally well. The photography is stagy, but gives Suddenly a claustrophobic atmosphere, and makes the tension a fever pitch. At 75 minutes, not a second is superfluous, and the dialogue exceptionally builds up characterization that gets us into the mind of the main assassin character, masterfully played by Frank Sinatra. Its plot and style may be unspectacular, but it has some good quirks.
Between two moralizing speeches, director Lewis Allen manages to deliver a good little B thriller. I particularly liked a lot how the hostages get rid of one of the hitmen. A scene that deserves to stay in the cinema annals. A DVD zone it's short, it's hot, its' good.
Solid old-fashioned thriller of confinement is horribly dated at times, but works due to a strong premise, well-crafted suspense, and an excellent, surprising performance by Frank Sinatra as the psychotic assassin. Only a minor classic, but solid entertainment for classic movie fans.