The necromancers

Technically part of the palace staff as they are under the orders of the king and their base is in one of the aisle of the palace.

"hort haired men he had seen once at the market. Well, one of them was bald, but the other one had very short hair, black on his pallid skin. Both had been clad in a formal and vaguely clerical regalia, their vague smile more threatening than humouring, and their gait the one of people used to dispose of life as casually as breathing.

Yes, he remembered now, necromancers also had short hair."