Doppelgängers

I absolutely love the theme of doppelgängers and I couldn’t even tell you why, but I am looking for books that explore this concept.

I have not read The Double by Dostoyevsky but it is on my list.

I have read the Edgar Allen Poe short story “William Wilson”.

I read Dark Matter by Blake Crouch. It was OK but did not scratch that itch like I was hoping it would.

I just got a book from the library called Downfall by Mark Rubinstein which sounds promising.

TIA!