Contains spoilers for this episode and earlier episodes.
A construction-site collapse traps three workers, and Lightman and Gillian are called to find out whether sabotage caused it. The contractor, city engineer and mayor each conceal information about the project. A witness's confused timing delays the search, while a camera lowered into the rubble lets the team question the trapped men. Jered Blunt's fear attracts suspicion, and his complaints to the company initially make him look like a possible saboteur.
Blunt has actually concealed multiple sclerosis because he needs his job. His shaking hands made him drop a blowtorch, but the buried landfill beneath the building explains why that accident caused an explosion. The engineer accepted money to approve the site without inspecting it. Lightman warns rescuers that their drill could ignite more methane; a second explosion follows, and only two workers emerge. Blunt dies. The mayor is arrested after Lightman establishes that she knew about the landfill.
Torres and Loker also investigate an Internet entrepreneur's doubts about his fiancée, Nadia. A covert interview reveals that she knew he was wealthy when they met, contradicting her story. He storms out before hearing the rest, so Torres persuades him to return. Nadia's initial interest in his money does not mean she has no feelings for him now. The team shows him the fuller conversation and urges him to speak honestly with her about their relationship.