As described in the novels, the Apparat dresses in brown, ragged robes. He has dark, almost black eyes, a long, dark beard, and a mouth full of crowded yellow teeth with black, wolf-like gums.
The Apparat is a strange priest who appears to advise the King. He appears at court when Alina Starkov is asked to demonstrate her powers, and again when Alina is studying in the library. He tells her to come to him whenever she needs help and then proceeds to give her a book called Istorii Sankt'ya (The Lives of Saints). He then tells Alina that she will experience more suffering in the future, but she cannot tell if it is a threat or a warning.
When Alina and Mal are caught, they learn that the King has fallen sick and the Apparat was ruling in his stead.