Why did that thought pop into Sidlar’s head? Is it possible for biographical or other information—a favorite food, a musical taste, a unique phobia, a memory of a traumatic, even fatal, injury—to be transferred from one individual to another through the heart? It seems inconceivable. Yet this phenomenon may well occur. Documented cases are both extremely rare and utterly shocking. And one possible interpretation of these stories involves scientists questioning the conventional wisdom about how memories are created and retained.