Father Hayse was the priest who was asked by Karen and Eugene York to baptize their adopted daughter, Delia. Unfortunately, due to being Damien's biological child, the holy water felt to her like a sting of sulfuric acid. As Delia started whining from the water's touch, Karen and Gene take the baby away.
Later, when Hayse noticed a strange vibration of his tabletop cross, he knew something odd was happening. So, he rushed of to the chapel in an attempt to pray in front of the big cross. But he suffered a major heart-attack, and the candles, blew out just before he died,