Research Randy and The Mystery of Grandma's Half-Eaten Pie of Despair

Research Randy reads like YA, and can be if you want it to be. It's also a weird mash-up of cosmic horror, eldritch terrors, nostalgia trip and a meta love letter to Lovecraft's Cthulhu mythos.
The stars of a beloved series of children's books, the clever Research Randy and his supernaturally sensitive sister Charlie, solved many cases in the idyllic coastal town of Serenity Bay to the delight of many readers over the last 30 years.
But now, suddenly transported to the creepy hamlet of Effingmouth, they find themselves in a bizarre place where nothing is what it seems, people are strange and secretive, and something awful lurks in the shadows.
This might be a mystery they don't want to solve.