After Constable Nick of Aidensfield and Heartbeat fame's retirement, he helped create a small private police force of monk-constables serving Maddleskirk Abbey and its adjoining college. The body of an unknown man is discovered in a huge stone coffin in the crypt and Nick and DCS 'Nabber' Napier of the local constabulary welcome the assistance of the monk-constables. With help from retired Sgt Oscar Blaketon and ex-PC Alf Ventress, plus some input from Claude Jeremiah Greengrass, Nick's experience is put to the test as a killer stalks the hushed corridors of Maddleskirk Abbey.