It is about praying to Mary for help and comfort in our dying days
A widow's son was a student in a smal christian school.He would say Hail May every time he saw an image of Christ's mother.
One day he overhears kids singing the Latin Hymn Oh Almo Redemptorists.
He asked those kids the meaning of the song and they said it was about praying to Mary for help and comfort in our dying days.
The boy learn the hymn and sings it often. The Jews didn't liked that ,so a hired murder grabs him cuts his throat and throws him into the sewer.
His mother searches everywhere for him, she heard him singing Oh Alma Redemptorists from under the ground. His body is taken to the nearest Abbey but he continues singing. They asked him how was that possible and he said Christ's mother appeard as he was dying and put a grain in his tongue so that he had to sing until the grain was removed.
At the end the Abbot removes the grain and the boy dies peacefully, then he's buried in the Abbey