When wealthy collector Brander Merton buys a Coptic chalice, he doesn't intend to meet the same fate as the relic's two previous owners. But after an arrow strikes him dead, Father Brown must expose the cup's supposed curse.
A paranoid millionaire becomes obsessed with a priceless early Christian chalice and wins it at auction. He lives with it in an impervious citadel, but is killed by an arrow in the neck. The irrepressible Father Brown must sift through a plethora of red herrings to find the killer and his/her motive.—duke1029