The cartoon is a story-within-a-story. Daffy Duck is fed up with comedy and wants to try a dramatic act instead. He offers a script to the Warner Brothers executive "J.L.", called The Scarlet Pumpernickel, which he wrote himself (under the name "Daffy Dumas Duck.")
As Daffy reads the script to J.L., the cartoon cuts away to various scenes and then back to J.L.'s office. Each time, Daffy announces a page number. By the cartoon's end, the script has exceeded 2 thousand pages (movie scripts much in excess of 100 pages were usually rejected as too long back in those days).
In this script, the clumsy Scarlet Pumpernickel (Daffy) must save the Fair Lady Melissa from being married to a man she does not love, the Grand Duke (Sylvester) under the Lord High Chamberlain's (Porky Pig) orders. Melissa loves Scarlet, but her happy mood is extinguished in a heartbeat when the Chamberlain orders her to "Keep away from that masked band-d-d-d-d-a-desperand-d-d-d-d-that masked stinker!" The Chamberlain gets a brilliant plan and decides to marry Melissa to the Grand Duke in exchange for killing the Scarlet Pumpernickel.
As planned, the Scarlet Pumpernickel is drawn to town to interrupt the wedding. He arrives disguised as a noble and uses the disguise to research and develop his plan for rescuing Melissa. Storming the wedding ceremony through the use of a "ye olde Olympic Highjumper (a pin and a jab in the posterior) as she is walking up the aisle, he is instantly successful as Melissa tears herself from her father's arms and runs from the chapel, dragging Scarlet with her ("So what's to save?"). Scarlet takes her back to the inn where he was staying, and leaves briefly. The Grand Duke, in pursuit of Scarlet, stops for respite at the inn and spots Melissa on the staircase. He chases her and is bearing down upon her when Scarlet swings in. Notably in this segment of the plot there is a running gag in which Daffy compares his own daring stunts with those of Errol Flynn.
The Grand Duke and the Scarlet Pumpernickel engage in an intense duel, but no conclusive ending is given as to who ultimately wins the battle and what happens at the end. Daffy, as the scriptwriter, either having only thought of the beginning and middle of the story or lost the rest of his script underneath a huge pile of pages, and being pressured by the enthusiastic "J.L.", overdoes the ending as an unlikely series of random and accelerating natural disasters, including a broken dam, an erupting volcano, and skyrocketing food prices (most notably "kreplach"), to which J.L. asks, "is that all?" At his wit's end, Daffy shoots through his hat in exhaustion, as if representing the Scarlet Pumpernickel committing suicide, commenting, "It's getting so you have to kill yourself to sell a story around here".
Who does Daffy read the script to ?
J.L