Krajensky was a Federation ambassador and considered an expert on the Tzenkethi. Unbeknownst to the Federation Krajensky was replaced by a Changeling in 2371 while on his way to Risa. Later that year the Changeling posing as Krajensky visited Deep Space 9 and concocted a ruse about a coup on the Tzenketh in an attempt to start a war between the Federation and the Tzenkethi. The Changeling impostor was killed by Odo and his plot was foiled. (DS9: "The Adversary")