THE NCIS TEAM IS PLACED IN QUARANTINE WHEN AN ENVELOPE ARRIVES WITH A MYSTERIOUS POWDER INSIDE ON "NCIS," TUESDAY, MAY 10

Steven Eckholdt ("My Big Fat Greek Life") and Mariette Hartley ("One Life To Live") Guest Star

"SWAK" -- When a letter sealed with a kiss is delivered to NCIS, Tony assumes it's for him and opens it, only to release a mysterious powder into the NCIS squad room, on NCIS, Tuesday, May 10 (8:00-9:00 PM, ET/PT) on the CBS Television Network. Dennis Smith directed the episode from a script by Executive Producer Donald P. Bellisario.

Steven Eckholdt ("My Big Fat Greek Life") guest stars as the doctor who treats the infected NCIS agent. Mariette Hartley ("One Life To Live") guest stars as a potential suspect.

Gibbs and the team are forced into quarantine in the NCIS autopsy room pending the results of tests to identify the strange powder. As Abby discovers the substance is a genetically altered version of the plague, Tony and Kate are placed in a bio-hazard isolation ward for fear of exposure. In the clear of the deadly virus, Gibbs and McGee race to track down who sent the letter before the deadly plague destroys one of their team members.

NCIS Special Agent Leroy Jethro Gibbs: Mark Harmon
NCIS Special Agent Caitlin Todd: Sasha Alexander
NCIS Special Agent Anthony DiNozzo: Michael Weatherly
Dr. Donald "Ducky" Mallard: David McCallum
Abby Sciuto: Pauley Perrette
NCIS Agent Timothy McGee: Sean Murray
Jimmy Palmer: Brian Dietzen
NCIS Special Agent Cassie Yates: Tamara Taylor
Navy Cmdr. Dr. Brad Pitt: Steven Eckholdt
Navy Nurse Lt. Emma Ingham: Kelsey Oldershaw
Hanna Lowell: Mariette Hartley
Sarah Lowel: Olivia Burnette
Security Guard: Ty Upshaw
Receptionist: Bibi Amos
Dr. Pandy: Rizwan Manji

RATING: To Be Announced