The EnterpriseTM discovers a lifeless Federation research vessel orbiting a planet hidden behind a mysterious energy shield. Despite the objections of his senior officers, Captain Picard and an away team beam over in search of the missing crew, and they vanish as well. Riker assumes command, and soon he discovers another problem besides the disappearance of his captain for a mysterious disease has struck the Enterprise crew. Riker races against time to unravel the secrets of the planet below in order to save his captain and the crew.