Following the Andorian attack on the Gorn using the Discovery, the Gorn Hegemony declared war on the Federation, moving into Federation space and destroying a Federation outpost. The Discovery was sent to the planet of Echo III, a system near Gorn space which had previously refused entry into the Federation, in order to secure the border with the Gorn. As the ship entered the system, the crew noted that the engines were acting strangely as a result of the nanorobots that Lt. Commander Dexter injected into the system during the Andorian attack on the Discovery.
After rejecting Chip’s plan to frame the Gorn for an attack on the native Cinnabar, Captain Taggert beamed down to the planet with an away team of the characters and some redshirts. The party was greeted by a diplomat named Melzara in the beautiful city of Last Peace, where they began to make the case that the Gorn threat could soon affect the Cinnabar directly. However, before negotiations could move very far, a group of men dressed in black entered the room and placed Captain Taggert under arrest…for thoughtcrime.
Back on the ship, the characters learned that Captain Taggert was accused of illegal thoughts involving the overthrow of the entire planetary government, a potentially capital crime. Commander McCracken protested that the captain was a foreign diplomat ignorant of the planet’s legal system, but Melzara refused to release him. As the two science officers began working on a device that could potentially block psychic abilities, Chip commandeered the transporter room and beamed himself down to the planet in an attempt to rescue the captain. Unfortunately, he was quickly located and arrested by the planet’s psychic police, the Eye. Chip was processed by the police and saw the captain in custody – held in a coma-like state with a device penetrating his skull.
The command crew debated how to proceed, understanding that securing an alliance with the Cinnabar was crucial given the Gorn situation. Lt. Hawthorne argued that Captain Taggert should stand trial for the crime, because Federation officers are typically held to local laws while traveling through the cosmos and because to do otherwise would jeopardize the mission. Lt. Commander Grant, the Chief of Security, argued that the Federation should not be bound by absurd laws and counseled in favor of military action. Commander McCracken agreed that thoughtcrime laws were unjust and arbitrary, but hesitated in ordering an attack due to the diplomatic nature of the mission.
McCracken beamed down to the planet’s surface in an attempt to appeal to Melzara, noting that the Cinnabar refusal to release the captain could threaten the Federation alliance with the planet and put its security at risk. During the meeting, Dr. Muriel noticed that one of the members of the Eye had some form of psychic shielding that appeared to be originating from some external source. McCracken was extremely convincing in talking with Melzara, questioning the morality of laws which did not prosecute actions, but before he could complete his argument, Chip burst into the room and assaulted the Cinnabar police officers. McCracken was able to convince the Cinnabar to release Chip, but lost his capital in attempting to negotiate for the captain’s release.
Back on the Discovery, the science team completed a prototype which appeared partially effective but which Dr. Muriel was still able to penetrate with her telepathy. The science officers wanted to attempt to create a device which could project violent thoughts into the citizens’ minds in order to show the government that their laws were flawed, but there was no time (!) as the captain’s trial was fast approaching. The crew was able to locate the external source of the psychic shielding that Muriel had detected and figured out how to block that shielding, but they realized that they would have to do so from the source.
McCracken and Will Nye beamed down to have another conversation with Melzara, ostensibly to protest the captain’s unethical treatment in custody, but in actuality to attempt to provoke the suspicious member of the Eye into thoughtcrime. Meanwhile, Kirby, Koller, and Chip beamed to the source of the psychic shielding only to discover a machine being administered by a group of Romulans! Kirby and company were able to block the shield’s emanations just as McCracken did in fact provoke the suspicious Eye member to violence against him, after which Kirby notified McCracken that Romulans were present in the system. The Romulans retreated, but not before killing a redshirt and badly wounding Koller. Melzara ordered that everyone in her location be arrested, so the other team beamed back to the ship to help sort things out.
The Cinnabar informed Lt. Commander Kirby that they were placing the entire ship under arrest – when Kirby refused to submit, they broke contact and used command codes stolen from the captain’s mind to lock down the ship’s systems. Koller realized that it would be possible to use the nanorobots within the ship to break the Cinnabar control, but as soon as he did so the Cinnabar orbital battle station opened fire on the Discovery! The Discovery began evasive maneuvers as Koller desperately attempted to use the nanobots to force the Romulan ship that they knew was present into view. He did so, the Romulans made their escape, and peace was restored. The Cinnabar immediately released the captain, and McCracken asked that they reconsider their thoughtcrime laws based on the incident.