London Police Superintendent Thomas Pitt was tasked with attending a secret conference on Irish self-government in order to prevent possible clashes between “sworn friends” - Irish Catholics and Protestants. According to the official protocol, his wife Charlotte also went with the policeman - especially since the meeting was organized at Ashward Hall, the country house of Charlotte's younger sister. But Thomas did not succeed. Negotiations, already difficult, were disrupted by the tragic death of Minister Greville, the mediator between the Irish factions. Gradually, Thomas and Charlotte came to a clear conclusion: the killer could not have entered the house from the outside. Therefore, he is one of those present and is still in the house. This means that the minister’s death may not be the last...