After the vandalization of a mosque, Mannion questions the mosque president, who reveals that the mosque has been receiving threats. Meanwhile, Temple and Debreno investigate two other hate crimes - both with similar scenarios - involving a rabbi and an African-American, respectively. Now, before racial and ethnic tensions escalate, Mannion and his team must get to the bottom of these crimes - unaware that the perpetrator is the last person they would suspect. 

A teacher, protesting the Board of Education's inattention to her cries, takes the board hostage at gunpoint, and Mannion must diffuse the situation. Frustrated by getting the run-around from the board and environmental agencies, she gives Mannion 12 hours to find answers to the teacher's and students' health problems before she opens fire. Mannion and his team must uncover a complex environmental cover-up while keeping the board and the teacher alive. Meanwhile, Ella asks Clive, the new man she is seeing and a lobbyist for the chemical industry, to look into the case from his end.