What's the Name of That Book??? discussion

The protagonist has a long conversation with a former executioner who is perfecting his old techniques in solitude. The protagonist has done some bad things in his life but doesn't remember them; the executioner seems to know about them. There are four dates involved?

Read 1 or 2 years ago (possibly not even a book?)



!!!!!Spoiler ahead!!!!!!



The executioner leaves his most refined execution technique for the protagonist, but somehow it doesn't work out? (there's a flaw of some sort)

Do you think it could be a short story?
Where did you read it? Online, library book, borrowed from friend, bought in store, etc.?
Author's gender?
Set a particular time and place?
Are there fantastical/paranormal/non-realistic elements?

The Master Executioner by Loren D. Estleman?

(Google search - site:www.goodreads.com mystery "executioner" techniques)