Only three chapters into the Barbara Nelson Scott mystery thriller All Saints' Day, reader Mary Toback has already deduced the killer of Father Blaine, the Vicar of St. Mary's of Glasgow, it was reported Tuesday. 'The angle of the stabs was consistent with a left-handed assailant,' Toback told reporters. 'And if you note the description of Bishop Argyll's desk on page 22, his quills are kept to the left of the writing tablet as he faces the desk.' Toback did not need to remind reporters that Argyll stands to benefit more than anyone from the appointment of MacGregor as the new Vicar. 