Ahh... very good. That makes sense.
The Sub-prefect is largely about how Butler got hounded for his writings on Stepinac and the Ustase.
In the Artukovich file, Butler traces war criminal Artukovich's stay in Ireland before he got to the US -- who supported him and housed he and his family while Artukovich hid out, before coming to the US.
Butler paid a heavy price for outing the Roman Catholic link to the Ustase -- as he says, it would have destroyed a man with less means.