The book contains fourteen homilies preached during World War II to the students of the Sisters of the Assumption at Aldenham Park. With a simple yet captivating style, Knox explains the Mass step by step, from the opening psalm to the conclusion. Although the liturgy he presents corresponds to the Tridentine Rite (due to the time it was written), the rich fruits of his reflection can easily be applied to the current Ordinary Form. It highlights the continuous action of the Holy Sacrifice of the Mass, in which the formula gives way to the mystery and man participates in his own salvation.
"First and foremost, the Mass means reminding ourselves of our Redemption—Jesus Christ was crucified for me. First and foremost, then, we are catching our breath at a great deliverance, and thanking God for it". (Ronald Knox)