On the fourth anniversary of the Wolf 359 attack and the death of his wife, Commander Sisko tries to evade the painful reminder by walking around the station. On the Promenade, he meets a woman who identifies herself as Fenna, and though a spark of fascination ignites between them, she disappears without a trace moments later. The next day, despite Fenna's vanishing act, Sisko carries out his duties, including the preparation of the USS Prometheus to carry out a hazardous stellar ignition experiment under the auspices of Dr. Seyetik - whose wife, as it so happens, turns out to be Fenna...or a duplicate of her. En route to the potentially deadly site of a dead star via the Prometheus, Sisko struggles to decipher Fenna's secret.
