Preston, 1741. The drowning of drunken publican Antony Egan is no surprise - even if it comes as an unpleasant shock to coroner Titus Cragg, whose wife was the old man's niece. But he does his duty to the letter, and the inquest's verdict is accidental death. Meanwhile the town is agog with rumour and faction, as the General Election is only a week away and the two local seats are to be contested by four rival candidates.

But Cragg's close friend, Dr Luke Fidelis, finds evidence to cast doubt on the events leading to Egan's demise. Soon suspicions are further roused when a well-to-do farmer collapses and it appears he was in town on political business. Is there a conspiracy afoot? The Mayor and Council have their own way of imposing order, but Cragg is determined not to be swayed by their pressure. With the help of Fidelis's scientific ingenuity the true criminals are brought to light . . .