Original publication: 1963, Atlantic-Little, Brown
From the flap:
"Once upon a time, far up in the mountains of Simeon, lived a young girl by the name of Allison. Late one afternoon in spring she was startled by the sight of a fleeing unicorn. No sooner had she sent the beautiful animal to safety than Allison was snatched from under the pounding hoofs of the horses by Basil, Prince of Simeon.
Allison and Basil fell deeply in love, but the wicked Queen refused permission for their marriage unless Allison could capture and put in golden cages seven fabulous creatures: a Chimera, a Dragon, a Harpy, a Gryphon, a Salamander, a Mermaid, and a Phoenix. What was more, she must deliver to Queen of Simeon the Secret of Life Itself in a box the color of a rainbow.
Allison was a resourceful girl. She was brave and she had a sense of humor, but above all she loved Basil. She had saved the life of theUnicorn and now, surely, the most magical of beasts would help her in return.
In the best fairy-tale tradition, Mrs. Cameron tells how Allison won her Prince and defeated the wicked Queen. Allison also won the hearts of everyone in court all the way from the little King, his ministers Catchpenny and Placepursal, and his two counselors Tintagruel and Fantalet, down to Rolly Tunket, the lowliest potboy. And we are sure she will win the readers of The Beast with the Magical Horn as well."
As with The Terrible Churnadryne and The Mysterious Christmas Shell, Beth and Joe Krush were called upon to provide illustrations. Unlike those previous books, the Krushes were allowed color and a large format in which to work. On several drawings, instead of their usual thin-lined, inkwashed work, they adopted a bolder style using lithography, to make the story feel authentically Medieval. Other illustrations are ink with graphite shading, but still with a heavier line that the Krushes typically employed.
Eleanor was thrilled with their work. In a September 1963 letter to Beth she wrote: "I see the results of your research everywhere, particularly in the feast scene where the nefs stand in front of the kings. What an individual that man is at the end of the table on the left-hand side! Of the colored illustrations, my two favorites are the on of the Unicorn and Allison opposite the first page of the story, and the one of the knights surrounding Basil and Allison when he has been wounded."
And she was even happier with the book's cover: "Ian and I were so happy when we took out the book jacket [for Beast] that we hugged each other — we really have never been so thrilled with anything connected with my books as this. The colors are simply beautiful — that rich deep apricot is perfect as a background for the magenta and blue-green, and the style, the two figures, the ribbons above and below, the lovely unicorn, the tapestry background scattered with flowers — all is perfect."