A man from Odo's past comes to the space station and is found murdered. Naturally, suspicion falls on the alien Changeling who had sent him to jail and was seen to have fought with him on the promenade. Sisko and his staff must find a way to clear Odo of Ibudon's murder. Meanwhile, Keiko, restless at having nothing to do on the station as a botanist, decides to open a school for the children living on the station.