A caricature of Alfred Hitchcock — the shadow of a bear walking up to a silhouette of himself — appears in the opening segment. In a Hitchcock-like accent, the bear announces tonight's story "about a murder."
As Sylvester waits in an alley trash can, Granny bids Tweety good night. After Granny leaves to visit a neighbor, Sylvester sneaks into the apartment and stacks a bunch of furniture to reach the caged bird. However, Sylvester loses his balance, knocking down the cage and knocking himself unconscious. Tweety escapes unscathed but decides to hide in another room.
When Sylvester comes to, he notices a bird feather on his lip, shortly before he overhears Granny about to return home. Sylvester flees the apartment and down the alley, when "Hitchcock" begins talking to Sylvester — "Well, you did it, didn't you? You got rid of that helpless little bird, (and) menace to society once and for all" — suggesting to the cat that, while unconscious, he swallowed Tweety and that the canary is now dead. Sylvester laughs off the suggestion that he committed murder and that he will probably get away with his actions, until he hears sirens and sees the newspaper headline "Police hunt 'The Cat'" (referring to a criminal who has menaced the city, although Sylvester worries he may be the suspect the authorities are after).
Sylvester flees to a nearest house to attempt to forget Hitchcock's taunts that he wishes "you could get away from your conscience." However, turning on the radio for music — the announcer flubs his lines to say, "Your local company will present gas chamber music ... I mean, your local gas company will present chamber music for your enjoyment" — and trying to read a story about a family of birds (the baby bird fits Tweety's description) turns the cat into a nervous wreck. The cat eventually wears a groove through the floor (and falls through it).
Eventually, a jittery Sylvester downs several cups of coffee and smokes six cigarettes before trying to get some sleep (see "Censorship"). However, he spends five agonizing hours in bed before snapping:
12:03 AM: Sylvester has hidden himself behind the bed.
1:21 AM: Sylvester is lying across the bed.
2:50 AM: Sylvester is lying in the bed, face down.
4:44 AM: Sylvester lies in the bed, his feet on the pillow.
5:07 AM: Sylvester lies in bed, his eyes are red, which the camera zooms to his eyes. He jumps up, screams and goes to get some sedatives.
The cat eats handfuls of sedatives (again, see "Censorship"), then collapses into tears, crying that he is a normal pussy cat and that other cats have eaten birds. Hitchcock suggests to Sylvester that he give himself up and accept the consequences. The cat takes the recommendation to heart and flees to Granny's house to admit his "crime" ... until he sees the bird safe and sound, sleeping in his cage. Sylvester is overjoyed, grabs the bird and begins to kiss him. However, the taste of the bird leaves the cat wanting to eat his prey. Granny comes in just in time and shoos Sylvester away with her broom. Tweety observes, "That puddy tat gonna have an awful headache in da morning!"
Hitchcock attempts to relate the moral: "In the words of The Bard, 'Conscience makes cowards of us all!'" Sylvester (offscreen) throws a brick at the bear and tells him: "Ah, shaddap!". The bear says "Good evening," then walks off with a lump on his head, the lump also having grown on his outline as the cartoon fades out.
On CBS, the part after Sylvester falls through the groove through the floor where Sylvester is nervously chain-smoking and downing two cups of coffee was cut.
On ABC, the part after Sylvester tries to get some sleep where Sylvester ingests a bottle of sleeping pills (while rubbing some under his arms and on his head), was cut (it should be noted that the quick cut to him on the ground crying after he ingests the pills exists on all current versions and may or may not be an edit done before the short went into theatrical release). ABC also shortened Granny beating Sylvester from six times to three.
The Cartoon Network version of this cartoon cuts out both drug scenes that were edited out on CBS and ABC. Originally, Cartoon Network only edited out the scene of Sylvester chain-smoking and downing two cups of coffee, but left the pill ingestion scene intact.