Mass in St. Germain-en-Laye

My husband enjoyed the trip outside of Paris to Chartres so much today that he wants to leave town again tomorrow--and so we intend to travel via RER A to St. Germain-en-Laye to attend Sunday Mass at either 10 a.m. or 11:30 a.m. at the parish church where the praecordia of James II, Mary Beatrice and their daughter Louise are interred. Then we plan to visit the chateau, which today houses the Musee des Antiquities Nationales.