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 cartoons 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 Chamberlains (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 fathers arms and runs from the chapel, dragging Scarlet with her ("So whats 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 surprisingly, J.L. asks, "is that all?" At his wits end, Daffy shoots through his hat in exhaustion, as if representing the Scarlet Pumpernickel committing suicide, commenting, "Its getting so you have to kill yourself to sell a story around here".
This is notable among Looney Tunes shorts for its unusually large cast of "star" characters (which, in addition to Daffy, Porky, and Sylvester, includes Elmer Fudd, Henery Hawk and Mama Bear from Jones Three Bears series). The only well-known characters to not star in this cartoon (among those that had been in cartoons already) were Bugs Bunny, Foghorn Leghorn, Tweety Bird and Yosemite Sam (Foghorn was exclusive to Robert McKimson, the latter two were used mainly by Friz Freleng). It was also the only cartoon directed by Chuck Jones in which he used Sylvester in a speaking role.
Mel Blanc voices Elmer Fudd, who plays the role of an innkeeper here. Elmer was originally voiced by Arthur Q. Bryan, but since the character had only one line of dialogue, Mel Blanc was told to go ahead and imitate Bryans voice for the character. Blanc did not like imitating, however, believing it to be stealing from another actor.
Although the title (invoking a type of bread instead of a flower) is a pun on The Scarlet Pimpernel, the Pumpernickel is given a portrayal closer to that of Robin Hood: in one scene, after Daffy fails to perform a stunt, he mutters, "Thats funny - that never happens to Errol Flynn," and his costumed appearance is more like Zorro, with cape, mask and sword, none of which the Pimpernel used. His alter ego, the "Nobleman disguise," is, however, more in line with wealthy English fop Sir Percy Blakeney of the Pimpernel fame.
The Scarlet Pumpernickel is available, uncensored, digitally restored and uncut on Looney Tunes Golden Collection: Volume 1, Disc 2. It is also available on The Essential Daffy Duck", the Carrotblanca VHS and the "Looney Tunes Collectors Edition: Running Amuck" VHS from Columbia House.