A team of Cardassian scientists comes to visit the station to help set up a subspace communications relay in the Gamma Quadrant. Suddenly a Vedek, named Yarka, wants to speak with Sisko. He brings a warning from the prophets and advises to refuse Cardassians access to the station. He refers to Trakor's third prophecy which tells of 3 vipers - the Cardassians - who return to their nest in the sky - Deep Space Nine - which ultimately leads to the destruction of the Celestial Temple - the wormhole. Sisko and Kira dismiss it at first, since only two Cardassians scientists are coming. But, when a third Cardassian scientist arrives, Kira begins to give the prophecy credence. With more and more of the predictions are coming true, Sisko must make a choice: his Federation duties, or his role as Emissary.
—Arnoud Tiele (imdb@tiele.nl)