A Navy lieutenant on shore leave dies of the bubonic plague, sending the New Orleans team into a tailspin to locate all other sailers on liberty to control an outbreak and find the source. Special Agent Tony DiNozzo gives a helping hand.

While Special Agent Pride and the New Orleans team investigate a Russian sleeper agent who was involved with Abby’s brother, Luca, Sebastian flies to D.C. to partner with Abby on the forensics in the case. Also, Bishop drives through the night to deliver a package and work the case with the New Orleans team.

The crossover starts on NCIS S13E12 Sister City (I).