The Little Murders of Agatha Christie

In a snap of the finger (3x8)

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A murder is committed during a demonstration by Frédéric Light, a medium capable of communicating with the dead. If the obvious culprit seems to be Nicole, a spectator, Greco guesses that the solution is not so simple: would the murder have been committed by hypnosis? Greco, fascinated by Light, gets in touch with her deceased mother. Rose calls on an expert to prove the medium's quackery.