Book about leprechauns, a war between two warlocks, and candles

Question

There's a really good book I read back in 2007 that I can't remember the name of and have no idea how to find.

I only remember bits and pieces, so I'll list what I remember.

The book focused on a war between two warlocks (or something).

There's a guy that thinks that he can see a candle in peoples head. If the candle is lit, that means that they're alive, and if he blows out the candle they die.

There's a scene where he fights one of the magician, and he bangs on a wall and birds fly out of the wall.

It also explores ideas of mirror dimensions and gives detailed instructions on how to catch a leprechaun.

I think the guy also thought that he was going crazy, and then while living alone he started to think that maybe he wasn't.

It was a thick book.

That's all I really remember, I hope that's enough.

Answer 1

It sounds a bit like Jonathan Strange & Mr Norrell by Susanna Clarke.

It follows the two title characters who are initially working together but later feud. There is some time given to trying to track/capture fairies.

Wiki mentions a character using a mirror to move between locations in the 3rd act/part

Jonathon Strange definitely sees candles burning inside people's heads as he goes a bit insane towards the end.

“May I ask you something?" Dr Greysteel nodded."Are you not afraid that it will go out?"

"What will go out?" asked Dr Greysteel.

"The candle," Strange gestured to Dr Greysteel's forehead. "The candle inside your head.”

(quote from https://www.goodreads.com/work/quotes/3921305-jonathan-strange-mr-norrell?page=2)