The Fearsome Foursome

I'm curious whether the author wanted to introduce themes of bravery and friendship through supernatural elements or if it was inspired by personal experiences with stories about ghosts.

The book manages to be spooky without scaring too much — I loved the mix, but I wonder if others found it perfectly pitched or a bit too lighthearted at times.

Each member of the Fearsome Foursome has such distinct traits — I wonder what inspired their individual quirks and how much of their personalities came from the author's own childhood or imagination.