Voyager is orbiting the Mari Homeworld, as her crew trade for supplies. While Captain Janeway and B'Elanna Torres are negotiating for a resonator coil, someone bumps into Torres, momentarily irritating her. She calms herself, shrugging it off as an accident. Later that day, several of Voyager`s crew witness a fight in the market place between two Mari. After questioning the crew, the Mari constable determines B'Elanna's angry thought earlier that day has been transmitted telepathically to the aggressor, and thus she is the more guilty of the two. She is sentenced to undergo memory modification to remove the thought, as is the aggressor. Janeway protests, as the modification process carries the risk of neurological damage. Before Janeway can unearth enough evidence they try to get Torres out, another attack occurs with the same memory, indicating that it is still in circulation. Unfortunately this attack ends with a murder. Tuvok goes undercover and finds an illicit memory trade in which the salesman of the resonator coil is a key figure. He determines that B'Elanna's memory was goaded from her in order to be resold, but it was too violent to contain, and thus the outbursts among the Mari. Torres is released due to this new evidence, just moments before her brain was to be probed.