From Amazon.co.uk:
When the body of a theology student is found on a desolate stretch of East Anglian coast, his wealthy father demands that Scotland Yard should re-examine the verdict of accidental death. Commander Adam Dalgliesh agrees to visit the young man's theological college, St Anselm's - a place he knew as a boy - expecting a nostalgic return to old haunts and a straightforward examination of the evidence. Instead he finds himself embroiled in intrigue, conflict and dangerous secrets as the college is torn apart by a sacrilegious and horrifying murder.

Left at the Street Library.

Release #20 for the 2021 Tick Tock Challenge.
Release #23 for the 2021 Spook-Tacular Challenge.
Release #23 for the 2021 Movie Books Challenge.