Late-mannerist canvas of Our Lady of Mount Carmel (Madonna del Carmine) with Sts. Sebastian and Gregory the Great with the souls in Purgatory.
This is the Purgatory Chapel of the Castel Nuovo in Napoli (Naples).
A lot of these chapels were constructed after the Council of Trent to instruct the faithful. This one was built between 1580-1581 by the Spanish viceroys. It's next to the main chapel of the castle, now just a museum.