The history of the Catholic Parish of Chiswick is quite interesting. It would appear that the first priests to work in Chiswick were Benedictines who opened a chapel in Acton right before Catholic Emancipation. In 1850, a secular priest was appointed, with the result that a chapel was soon opened in Turnham Green as well in Chiswick High Road on the north side. A school was started about 1855, the site of the present church was bought in 1864. In the night of the 19th February 1944, one of the last bombs to fall on Britain landed next to the church at the top of Dukes Avenue, and the east wall took the full force of the explosion. The church features those pretty red bricks of the late 1800s which are typical for the buildings designed and errected for the 19th-century bourgeoisie in Chiswick. The same kind of bricks you will find on other churches in the area (check for the Church Micro Series traditional and multi-caches in Chiswick, there should be quite a few!). It also features a very high tower which is quite surprinsing for a church right on Chiswick High Road. Take a look inside the church if it's open!
At the coordinates of the multi, you won't find any cache but the clues needed to complete the first stage of the multi.
Stage 1 - (at the given coordinates for the multi). At these coordinates, you should face a large red board with golden letters on the outside wall of the church (on Chiswick High Road, behind the metal fence). Look for the phone number: it's C2C H994 2H77.
For stage 2 and 3, and to learn more about how to calculate the final coordinates: see description of the waypoints / stages and of the final location. You can check if you calculate it the final GZ right by visiting geocheck.org.