Suggest me a book where “everything is connected”

I am looking for a book with one of those endings where everything was connected and fate comes together so satisfyingly. And preferably one with an effervescent or quirky vibe. If you’ve read or seen Douglas Adams (specifically “Dirk Gently’s Holistic Detective Agency”), or read Vonnegut’s “Sirens of Titan”, that’s the magic I’m trying to capture again. Thanks!