Lisbon and the relics of the Saints

Relics and busts of saints in St Roque, Lisbon

November has been a very busy month in my bread and butter job, which hasn't left time for continuing the novel. 
However on a trip to Lisbon at the end of October I visited a great church - the Church of St Roque.
Like all towns which were centres of trade in the past, everybody lived in fear of the plague. St Roque was a plague survivor and became the person you prayed to when you were feeling poorly.
In a chapel of this church I found this amazing collection of saintly bones. What made this collection unusual was that there was also an artist's impression of what the saint looked like in bust form, sitting on top of the glass casket with the bones, something I've never seen before. For some reason they all seemed to be female saints in this chapel (and fairly hot saints according to the artist).
Now I'll give you three guesses what Celia and the Colonel are going to find in the hidden chamber in the chapel as described in Chapter 31...