Contains spoilers for this episode and earlier episodes.
An old friend, Jeffrey Buchanan, hires Lightman to investigate the theft of a pharmaceutical company's insulin formula. The suspected thief says she was looking for evidence that the original drug causes strokes. Lightman follows her claim to the laboratory that tested it and discovers that the company dismissed findings it did not like. His loyalty to Jeffrey makes him slow to accept Torres's warning that his friend is concealing something.
Jeffrey admits an affair with the company's chief executive, Erica Vandeman, but denies knowing that she altered a study. Lightman warns him to stay away from her, then lets investigators listen when he goes straight to her. Erica admits that delaying the drug would have bankrupted the business and that she hoped to fix its dangers after launch. Her attempt to hide those risks is exposed without proving Jeffrey was the person who falsified the results.
Gillian and Loker meanwhile assist negotiations for two Americans imprisoned in Yemen. Nicole is secretly an American intelligence operative, making officials more interested in saving her than her brother Marcus. The team presses for both releases and identifies the deputy ambassador's desire for recognition. A deal combining non-military demands with a White House invitation secures their freedom. Afterwards, Lightman sees Alec meeting a young woman, adding to his suspicion that Gillian's husband is lying about working late.