*"Do not doubt me, my friends; you shall all be dead before morning."* New Orleans, 1930. Eight guests are invited to a party at a luxurious penthouse apartment, yet on arrival it turns out that no one knows who their mysterious 'Host' actually is. The latter does not openly appear, but instead communicates with the guests by radio broadcast. What the Host has to tell the group is chilling: that every hour, one of them will die. Despite putting the guests on their guard, the prophecy starts to come horribly true, each demise occurring in bizarre and ghastly fashion. As the dwindling band of survivors grows increasingly tense, their revelations to each other begin to explain why they have been chosen for this macabre gathering and invoke the nighmarish thought that the mysterious Host is one of *them*. The burning question becomes: will any of the party survive, including the Host...? *The Invisible Host* (1930) established one of the best-loved and most durable set-ups in classic mystery fiction. It was most famously to recur in Agatha Christie's *And Then There Were None* (1939). The extent of Christie's debt to her predecessor is open to conjecture (and the subject is discussed in our new introduction, by crime fiction historian Curtis Evans).