According to the sean-caoide in my district Patrick Lundy. There lived in the village of barns two brothers who entered Religious Orders and became Priests namely Fr. Patrick and Fr. Dominick Mac Faden.
Owing to the Penal laws being in force those two brothers had to work like civilians and in order to disguise themselves they dressed as civilians. When they were celebrating Holy Mass they would be punished very severly and perhaps put to death.
Those priests sent messages to the people of the surrounding villages to assemble in a certain valley along an ivy