The Priory of Finchelsea XIII.

Lil Barton followed Miss Carlton through the maze of passages underneath the Church of Christ the King, Gordon Square. Lil's mind was racing. What had Dr. Llewellyn Pryce-Rees-Evans-Jones meant by his cryptic messages? Was it just to implicate her in his murder, or did it have some deeper meaning?
"Kathy! What was the first clue?" she asked.
"Ha Cohen Ha Gadol!"
"Ha Cohen... Kathy, where would you expect to find the Jewish High Priest?"
"In the Temple."
"Sure..." Lil sighed. "And no temple. Unless... This building is owned by the Catholic Apostolic Church. They believed in the restoration of Apostles, but with the death of the last of the end-times apostles, they are in the wilderness... that's it! the wilderness! In the Wilderness the High Priest would be in the Tabernacle!"
"I don't get it."
"Church furnishings! I know this building, and I know the English Chapel. The people who built it, and the people who own it today, believe in the reservation of the Sacrament. It's a Romanist perversion, but it's done! And the structure in which the sacrament is reserved is called a Tabernacle. The Catholic Apostolic Church went in for big, elaborate tabernacles on their altars."
"So?"
"So it's a big box! Perfect for hiding things in!"