As chairman of a group of British peers and Irish movers and shakers interested in Northern Ireland, Baroness Troutbeck decides to hold a conference at a castle in the West of Ireland to sort out the Irish question once and for all. Robert Amiss is press-ganged into being conference organiser.

Those assembled include Finbar O'Gorman, a romantic second-generation Irish Old Etonian who wants a United Ireland tomorrow; Lord Galveston, a choleric High Tory who wants the Gurkhas sent in to deal summarily with all suspected terrorists; Buster McKeown, a fundamentalist Presbyterian minister who sees Rome under every bed; Maire Ni Ghabhain, a member of the MOPE Party (Most Oppressed People Ever) who drones on all the time about the penal laws, the famine and police harassment; and the journalist Gervase Shore, who has been covering Northern Ireland for twenty years and is almost expiring from cynicism and ennui.

When a delegate plummets off the battlements, the warring factions accuse one another of murder and the authorities start to point fingers at each other for reasons that appear totally irrational to outsiders. In the ensuing chaos, the Irish police, bewildered by clashing cultures and worn down by the chivvying of Baroness Troutbeck, gladly accept unofficial help from Robert Amiss.