need help remembering a book title

Hello, I am having a problem recalling the book which inspired me.

Basically the founders of the London Bridge covenant arranged for the building of London bridge according to principles of Hermetic Architecture and some experimentally integrated non-Hermetic sacrifices buried in the foundations of the bridge pylons/pillars, based off of some work by Flavia of Rosalaba. This caused the central pillar, located where the sound of the church bells of London was already muted, to have access to the entrance to an island/boulder in the magic regionne containing the Ur-Thames. There are some "odd side effects" from this experimental technique (eg anniversary of each sacrifice causes effects like everybody becomes Twilight Prone for that day) that the PCs are not fully aware of yet.

The idea of sacrifices in the bridge foundations came from some book where the King's Touch to cure the King's Evil was not a Blessing. Does anyone know what book I am referring to ?