The NCIS team must investigate when a Navy reservist is stabbed and his lab full of pesticides and insects is ransacked. Also, Kilbride offers Sam the interim operations manager position and Rountree thinks about his future.

When an ATF agent goes missing, the bureau seeks help from the NCIS team to investigate stolen military-grade weapons and locate the agent. Also, Callen and Anna continue to plan their wedding, Rountree's sister interviews for medical school and Sam encourages his father to take part in the drug trial.