The Altanex was a small Romulan cruiser starship that was in service in an alternate timeline. The ship was used as an espionage vessel and was equipped with several transmorphic cloaking devices. The Altanex was commanded by Centurion Karon. In the year 2400, the Altanex captured Jean-Luc Picard and Nog from the Utopia Planitia Fleet Yards. (DS9 - Millennium novel: The War of the Prophets)