The Ruin by Dervla McTiernan

I was reading Audre Lorde's Sister Outrider across the Christmas/New Year holidays.
Now, I've started my first new book of 2021 - The Ruin by Dervla McTiernan. It was a welcome Christmas gift and I love that is introduces me to an author that is new to me.
What's your first book of 2021?