The USS Enterprise visits the Botanica Four research space station, in orbit around Tanuga Four, where Commander William Riker is checking on the progress of Dr. Nel Apgar, a Tanugan scientist supposedly willing to provide the Federation with a new energy source. Riker, obviously agitated, transports back to the Enterprise - at which point the station explodes, killing Dr. Apgar. Riker is considered a prime suspect, and under Tanugan law is considered "guilty until proven innocent". Tanugan investigator Krag wants to extradite Riker immediately, but Captain Picard requests that a hearing be held aboard the Enterprise. Krag agrees to the hearing, which will involve the use of the ship's holodeck to recreate Botanica Four and the events aboard it from the point of view of Riker, Dr. Apgar, Apgar's wife Manua, and Tayna (Apgar's assistant). Each testimony shows Riker and Dr. Apgar, who was working on a method of generating powerful Krieger waves, having an angry discussion just before Riker beamed off the station, though the nature of the argument is different from each viewpoint. However, there is undeniable testimony that a forced energy pulse appeared to have been fired from where Riker stood, striking Apgar's Krieger wave energy converter and causing it to explode.
Meanwhile, as the hearing continues, the ship's crew detect waves of unknown radiation that temporarily interfere with the ship's systems. Further investigation shows the radiation appearing at precise intervals, at the same time as the planet-based field generator (used by Apgar in his research) is timed to activate. When Picard is told of this, he realizes what has happened, and demonstrates for the hearing's attendees. Apgar had actually created a working Krieger wave converter, but when the Federation arrived to check on the progress of the work, Apgar lied - in order to try to profit from weaponizing the technology. Apgar then tried to drive the Enterprise away by using the converter to strike and kill Riker; he intended to activate the converter at the moment that Riker beamed away, in order to make his death look like a transporter accident. However, the transporter field reflected the Krieger wave back to the converter and destroyed the station. Picard proves this by pointing out that the holodeck recreation of the converter, also completely functional, had been intercepting the generated field energy from the planet and created its own Krieger waves. Picard demonstrates by timing the holodeck program with the next field emission from the surface, which recreates the situation as Picard describes - and destroys the holographic simulation. Riker is exonerated, and the case is dismissed.