From the introduction:
The ancient grandfather clock in the hall seeks Justice. Impartially, impassively, it uses its considerable powers to weigh the measure of human lives, delivering deserts accordingly. Rare is the person who can bear the full weight of what he deserves.
Tonight, the clock has invited a small party to its house. The guests arrive, not knowing quite why they attend, but compelled to do so nonetheless. Over the course of the evening, dark secrets of the past will out, and the guests will be thrown into a nightmare world of their own making. The clock has its Justice when midnight tolls.