Contains spoilers for this episode and earlier episodes.
A soldier's accusation sends Lightman and Torres to Fort Meade, where Specialist Sheila Lake says Staff Sergeant Russell Scott raped her. Scott has passed a polygraph, but the interviews reveal that Lake is speaking for another woman. Rebecca Metz fled the Army after enduring repeated coercion from Scott. Finding her changes the investigation from testing Lake's account to establishing what Scott did to someone afraid to testify.
Scott describes Metz as his girlfriend and produces photographs to support his story. Metz explains that rejecting him would have meant driving the lead vehicle on dangerous convoys. Lightman stages a polygraph confrontation in which she claims she actually drove lead after refusing sex. Scott angrily insists she never performed that duty, exposing the arrangement he had concealed. He is arrested, while Torres learns that Lightman manipulated the demonstration rather than relying on the machine's verdict.
Gillian and Loker investigate a separate allegation that basketball player Earl White accepted money to attend a college. They discover that he has a painful degenerative condition and is raising his younger brother after their mother's death. His expected professional career cannot provide the security he hoped for. Gillian directs the consultancy's fee into a trust for his education after the scandal threatens his scholarship. The opening polygraph demonstration and the military case both belong to the drama's fictional approach to detecting deception.