Season 2, Episode 3:

The USS Lambda Paz, as part of the Kalandra Campaign, is assigned to a strike force on the outer reaches of the sector. Former Obsidian Order operatives aboard station Sentok Nor are feeding information to Starfleet Intelligence, which Section 31 believes is part of a more devastating plot that is a threat to both the Federation and Cardassian Union. Doctor Aurellan Markalis is recruited to infiltrate a mysterious Augment cabal.