The Holy Souls are those who have died in the state of grace but who are not yet free from all punishment due to their unforgiven venial sins and all other sins already forgiven for which satisfaction is still to be made. They are certain of entering Heaven, but first they must suffer in Purgatory. The Holy Souls cannot help themselves because for them the night has come, when o man can work (John 9:4). It is our great privilege of brotherhood that we can shorten their time of separation from god by our prayers, good works and especially, the Holy Sacrifice of the Mass.
Prayer for the Souls in Purgatory
My Jesus, by the sorrows Thou didst suffer in Thine agony in the Garden, in Thy scourging and crowing with thorns, in the way to Calvary, in Thy crucifixion and death, have mercy on the souls in purgatory, and especially on those that are most forsaken; do Thou deliver them from the dire torments they endure; call them and admit them to Thy most sweet embrace in paradise.
Our Father, Hail Mary, Eternal rest, etc.
Indulgence of 500 days
The Prayer Book, Catholic Press