FLOTUS Michelle Obama
U.S. first lady Michelle Obama gives a keynote speech to the Unite For Veterans Summit in Los Angeles, California, July 16, 2014. Obama is on a two-day swing through the Los Angeles area. REUTERS/David McNew (UNITED STATES - Tags: POLITICS)

Fans are in for another shocking and suspenseful episode of “NCIS,” as it nears the season finale and Michael Weatherly’s exit. The show returns with a brand new episode on Tuesday titled “Homefront,” which focuses on the lives of military spouses and children. US First Lady Michelle Obama makes a special appearance as herself, and she welcomes Leroy Jethro Gibbs (Mark Harmon) at the White House for a meaningful event for the troops’ families.

“24” vet Reiko Aylesworth has also signed as guest star on the episode titled “Homefront” as Anne Marshall, a deployed Marine Master Sergeant’s wife. They join other “NCIS” cast members who will also be featured on the upcoming episode, including Anthony DiNozzo (Michael Weatherly), Timothy McGee (Sean Murray), Eleanor Bishop (Emily Wickersham) and Jimmy Palmer (Brian Dietzen). Also appearing on the “NCIS” Season 13 episode 21 are Leon Vance (Rocky Carroll), Abby Sciuto (Pauley Perrette) and Dr Donald Mallard (David McCallum).

Spoiler alert! This update contains more "NCIS” Season 13 spoilers. Read on at your own risk if you have not watched the latest episode.

TV Guide reports that on Tuesday’s episode, Gibbs visits US First Lady Michelle Obama to participate in the “Joining Forces” roundtable with military spouses at the White House. Meanwhile, Gibbs also delves into a home invasion case that involves a 14-year-old. Elsewhere, Vance and Senior FBI agent Fornell fly all the way to London to investigate a case involving an escaped British spy.

“NCIS” also posted sneak peeks of its May 3 episode on its YouTube page. One preview video shows McGee trying to get the truth out of Henry, the boy who stops a home invasion. The “NCIS” team thinks there is more to the story, and McGee volunteers to talk to him. McGee and Henry talk about the problems and emotional issues of being a military man’s son. Later, Henry reveals that he got his dad’s gun from the safe because he fears for his life. Apparently, Henry witnessed Micky Doyle stab an unidentified man on a dark alley, and the killer saw him.

In another teaser, McGee shares this information with Gibbs. Meanwhile, Bishop expresses her concern on the unfair situation that Anna Marshall and other spouses of military men find themselves in. “When troops fight for the country, their families do, too,” she says. “Who fights for them?” Gibbs replies, “We do.” Bishop then says she wants to reach out to Joining Forces, an initiative that supports military veterans and their relatives. Gibbs says he already called them.

The Joining Forces initiative was launched by Michelle Obama with Dr Jill Biden, so it was a great achievement to have the First Lady as a special guest. “Initially, she was going to come and film with us here in Los Angeles, and then her schedule didn’t allow that,” executive producer Gary Glasberg told Parade.com. “They literally said, ‘Would you like to come and film at our house?’ We jumped at the opportunity. We are the first production to actually film inside the White House ever. ‘The West Wing filmed outside, but we were given the opportunity to go in and the First Lady was fantastic.”

KSite TV reports that Joe Spano (Senior FBI Agent T.C. Fornell), Randall Yarbrough (Micky Doyle), Sandra Nelson (Sandra Nelson), Benjamin Stockham (Henry Marshall), Adrian Sparks (Hugo Radcliffe), Pete Gardner (Detective Daniel Swanson), Zoe Perry (Harper’s Ferry Police Officer Kristin Fields), Elijah Mahar (Marine Master Sergeant David Marshall), Stephen Oyoung (Navy Captain Andrew Hubbard), Paul Holowaty (MI6 Officer) and Juliette Angelo (Emily Fornell) will also appear on “NCIS” Season 13 episode 22. “Homefront” is directed by Dennis Smith and written by Jennifer Corbett and Gina Lucita Monreal.

Find out what happens next on “NCIS” Season 13, which airs in the US on CBS every Tuesday, 8/7c.