Celtris III
From Star Trek : Freedom's Wiki
Celtris III is an uninhabited planet located in Cardassian space in the Celtris system.
In 2369, Starfleet Intelligence began monitoring bursts of theta-band subspace emissions from Celtris III, which typically indicate a metagenic device in operation. Since such devices are illegal, this lead Starfleet to believe that the Cardassians might have been operating a secret research lab somewhere beneath the planet's surface. However, the signal was faked just to lure Captain Jean-Luc Picard to the planet, who was an expert in theta radiation. During a secret mission on Celtris III, Picard was taken into custody and interrogated by Gul Madred. (TNG: "Chain of Command, Part I", "Chain of Command, Part II")
