A disreputable frontier planet where Picard was apparently vaporised in a bar in 2370, leading his officers to search its underworld for the killers.
Dessica II is a lawless world frequented by smugglers and mercenaries. It appears at the start of the seventh-season Next Generation episode Gambit, Part I.
In 2370 Picard goes missing while investigating the looting of an archaeological site. Riker, Troi, Worf and Crusher visit a bar on Dessica II in plain clothes, asking after him among suspicious patrons. A Yridian informant, once pressed, tells them that a group of mercenaries argued with a man matching Picard's description some weeks earlier and shot him, leaving nothing behind.
The crew return to the Enterprise-D to mourn, and Riker sets out to find those responsible. In fact the weapons used were modified to work as transporters, and Picard had been beamed to the mercenary ship, where he talked his way into the crew.