What happens when 2 serial killers begin to compete with each other? #Suspense #Crime #Thriller

in my opinion Shadow heart is the best book in the unsub Series so far but I have to remind you all that I have been familiar with all of the serial killers that inspired the first three books Samuel little I wasn't familiar with at all so I didn't have any clues as to what may be happening this one it was a whole new experience with me but it really left me breathless several times

I've been addicted to this series ever since I started a few weeks ago when my friend EV sent me the first book unsub I just started this series I haven't been able to stop