Plot:
Agents are on the watch for Commies. Gerhard Eisler is being watched.
Matt Czetic goes to see his mother. His brother isn't happy with Commie Matt who gets a call to see Eisler. It turns out that Matt is an undercover agent spying on the Commies for the FBI.

My refrigerator is running. So I need to go out and catch it...
At the meeting, Matt gets promoted to party organizer for the city. The communists want to raise riots and organize social unrests for divide and conquer.
Later, Matt reports to the FBI how the communists want to start race riots.
Steel mill, commies injury non-party guys so more party guys can join. Matt gets a call about his son, Dick. Dick has been getting into fights because his dad's a commie. Dick can't tolerate a commie father.

What do you do when you're not feeling patriotic enough?
That night, Matt writes a letter for his son just in case happens to him. Eve Merick, Dick's teacher, knows Matt and apparently is also a communist.

You have to be on the look. There are actually some card-carrying commies around...
Commies want to cripple steel mills. Matt has bugged the meeting. The FBI overhears and learns that Eve is to watch Matt.
Matt learns than his mother is getting sicker. Unfortunately, too late, he doesn't get to her before she passes away. His brother gets into a fight after the funeral.
Matt learns the letter is gone, and Eve took it and read it. She has been having a crisis of conscience. She keeps from reporting Matt to the commie leaders.
Matt wants to get out his cover. The FBI can't clear him yet. They play a recording where he learns that Eve kept from reporting him.

G-Men are known to dominate others by whoever has the largest piece of hankerchief on their ears.
Commies are planning a strike to get the steel workers strike and riot. When, Joe, Matt's brother, tries to cross the line, the fight ensues.

Tastes great!! LESS Filling!!

Where's the Maltese Falcon?
Afterwards, Matt learns about Eve's growing morals. She decides to report who she knows are commies. Matt talks with her to get out of Philadelphia before the leaders
want her exterminated with extreme prejudice.
One of the killer commies shoot an FBI agent when they miss Eve.
Train station, the commies are still after Eve. Matt comes to her rescue.
The commies want to insult the House Un-American Activities Committee and raise money through fascism.

Somehow paintings of Stalin and Lincoln side by side seem strange...
When North Korea invades South Korea that war will scare people. The leaders question Matt and start beating him when cops run to grab Matt on suspicion of murder
of a FBI agent.
In the car, they tell Matt how he'll finally testify in court about the communist leaders.
Before the trail, the attorneys are keeping Matt undercover for now... He's called and admits that he was working for the FBI and the evils of communism and the Soviet Union. Joe and Dick are so proud that Matt was never a commie.