While returning to Deep Space Nine, Odo and Chief O'Brien encounter another Changeling. This Changeling, like Odo, is one of the Hundred sent to explore the Alpha Quadrant. The Changeling, who calls himself Laas, has no knowledge of The Dominion or the Founders. He followed the runabout when he sensed Odo's presence, and is eager to learn more about their kind.

On DS9, Dr. Bashir confirms that Laas is not a Founder, and Captain Sisko allows Laas the freedom of the station as long as he remains in Odo's custody. The two changelings discuss their past. Laas reveals that he does not trust humanoids (who he refers to as "monoforms"), but neither does he support the Founders' agenda, and just wishes to avoid humanoids. When the two share the Great Link, Odo reveals he too would have left human space, had he not fallen in love with Major Kira.

As days pass, Laas attempts to convince Odo to embrace his Changeling heritage, and suggests they leave the station in order to find more of the Hundred and form their own Great Link. Odo is tempted, especially when Laas (who is much more apt at shapeshifting), helps him improve his skills. Matters are not helped, however, by Laas' disinterest in human friendship.

Laas causes a disturbance on the Promenade when he transforms into a fog. Emergency crews are sent to deal with what they think is a life-support malfunction, and are angered when they learn the truth. The commotion draws the attention of two Klingon officers visiting the station. Seeing what they assume is a Founder, they attack Laas with knives. Laas' shapeshifting allows him to both defend against the attack and kill one of the Klingons.

After news of the killing reaches Klingon High Command, they request that Laas be extradited to the Empire for trial. Kira, wanting to give Odo the opportunity to travel with his own, frees Laas and tells everyone that he escaped. Privately, she lets Odo know that Laas is waiting on Koralis III. Odo meets Laas on Koralis, but declines to leave with him. Odo tells Laas that he is wrong about the "solids" and that he is staying with Kira. Back on DS9, Odo shows his love and affection for Kira by transforming into a golden light, so that Kira can feel the closeness of the Great Link.

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