Series
There are 2 books in the Killing Commendatore series.
Abandoned by his wife, a portrait painter retreats to a mountain house once owned by a famous artist. Perched between weather and worlds, the house becomes a threshold where strange occurrences blur reality and dream, and a mysterious painting opens rifts in the fabric of existence.
All 2 books total 976 pages.
The Books Oracle — track the series you are partway through, and see what to read next.