An Ace Giant Double of Charlotte Armstrong novels

Today we have an Ace Giant Double featuring two novels; flip it over and you get the second novel! 

• Titles: The Better to Eat You & Mischief
• Author: Charlotte Armstrong (1905-1969). The best article I found about her was published on PopMatters in 2015 and written by Imran Khan, whose insights include: "Why Armstrong’s novels have never left the indelible impression that the works of her fellow female mystery-writers have may be the biggest mystery surrounding her. Like many authors of her ilk, Armstrong’s women were fearless investigators of their environments, digging for clues, crossing boundaries and generally engaging in what was considered a 'man’s work.' But her characters were more than just women combating the realms of male-dominated environs; they also re-envisioned the roles that were designed by women writers like Armstrong herself. Her women opened the same forbidden doors to the same cellars that the women in the stories of Agatha Christie and Patricia Wentworth did, scavenging the deep, dark depths of a mystery for some decisive clue. But Armstrong’s characters also opened doors for other reasons; widening the shafts on the predicaments of their intrinsic mysteries, their inner worlds were just as much up for cross-examination as were the murdering fiends of the author’s tales. Armstrong knew, in essence, that her stories were only as good as the women leading them."
• Cover illustrator: Unknown, to the best of my research, which is a real bummer. Cover illustrations for mid-century mystery novels are not nearly as well documented online as sci-fi and fantasy covers. If anyone knows, please leave a comment! 
• Is that a scary clown on the cover of The Better to Eat You? Yes.
• Does ... does the clown eat people? It's unclear.
• Publisher: Ace Books (G-521)
• Publication date: July 1965 (Mischief was originally published in 1950 & The Better to Eat You was originally published in 1954.)
• Pages: Mischief is 123 pages and The Better to Eat You is 164 pages.
• Format: Paperback
• Price: 50 cents
• Excerpt from The Better to Eat You: "Sarah sat before her typewriter, holding her head together with both hands. All the long train of her sorrows was dragging through her memory."
• Excerpt from Mischief: "Bunny listened politely to the story. When Mommy read, the story seemed more interesting. When Daddy read to her, it was interesting, too, although Daddy never did finish a story. He always got off to explaining something, and the explaining turned out to be another story."
• Film adaptation: Mischief was made into the 1952 movie Don't Bother to Knock, featuring Marilyn Monroe, Anne Bancroft and Elisha Cook Jr. It's considered to be one of Monroe's best acting performances.
• Mischief's rating on Goodreads: 3.63 stars (out of 5)
• Goodreads review excerpt: In 2016, E.G. wrote: "A chilling read, suspenseful to the end and a view of insanity that is very present and forceful. It is a dark read -- bordering on too dark -- and that sometimes makes the characters annoying."
• The Better to Eat You's rating on Goodreads: 3.58 stars (out of 5)
• Goodreads review excerpt: In 2018, Historygirl wrote: "This is a comic thriller. Truly scary but with a screwball comedy element. The Better to Eat You features an extended literary metaphor that gets funnier and funnier as the book goes on. It is also an excellent romance."
• But what about the clown?? I guess you'll have to find out for yourself.