I also enjoyed Red Dragon by Thomas Harris.

The whole Hannibal trilogy is one of my favorite series of books. (Red Dragon, Silence of the Lambs, and Hannibal; respectively.)

There's a fourth book, Hannibal Rising, that serves as a prequel/origin story for Hannibal Lecter. But it was written under duress by the author.

Thomas Harris didn't want to explain Hannibal's origin, as it removed the mystery surrounding his character. But Hannibal had become globally famous through the films, and Harris was basically told by the film producer, Dino De Laurentiis, that if he didn't write an origin story, someone else would. So in order to maintain some control over his own character, he begrudgingly wrote Hannibal Rising.

And it shows. The writing style of that book is very different from the other three. Unlike the trilogy, which has a way of weaving an intricate and mesmerizing story, Hannibal Rising just feels mechanical and methodical, like it's just checking boxes and getting to the point as quickly and efficiently as it can. It told a basic story, which was immediately pumped out as a low-budget B movie 2 months later.

If you get into the Hannibal books, I highly recommend skipping Hannibal Rising. It's poorly written and removes the mystique behind Hannibal Lecter.