As far as I know, The Secret Plan is the only picture book about bedtime that heavily features kittens communicating using Morse code.
What I didn't know was that Samuel F. B. Morse, the man who invented the telegraph, as well as the Code, was a painter before he turned to inventing. I saw one of his most famous works, Gallery of the Louvre at the National Gallery in Washington, DC.
Here's a visual way to remember the Morse alphabet (based on A.G. Reingold's chart.)
Useful when plotting your next sleepover.
For those more curious about Morse and his code:
A short biography of Morse is here.
There's also an interesting article from the New York Times here about a recent event called the Night of Nights, when the air was once again filled with "the music of Morse." (The article was also my first introduction to the term "radio squirrel.")
