One of the most intriguing cases of the Oxford professor and amateur detective Gideon Fell.
This murder could not have happened by definition, because no one could have approached millionaire Howard Brooks unnoticed on the open platform of a medieval castle tower practically in full view of witnesses, stabbed him—and vanished without a trace.
But… sometimes even the impossible happens.
The police are at a loss. And then Gideon Fell takes up the investigation—the only one who takes seriously the frightening and strange legends told about the old castle…