Gibbs (Mark Harmon) and the rest of the team look into the supposed suicide of a seemingly happy and successful Navy Lieutenant in the next episode of the action police procedural television series "NCIS." 

In the upcoming episode titled "Dark Secrets," its synopsis from TVGuide reveals that the team will be conducting a thorough investigation by talking to the Navy Lieutenant's family and friends from the past and the present. JAG Navy Captain Bud Roberts, Jr. (guest star Patrick Labyorteaux) will be providing vital information as he previously worked with the deceased. 

The trailer for "Dark Secret" describes the case to be investigated as "weird" and "fifty shades of twisted." In what is assumed to be the home of the deceased Navy Lieutenant, the team finds numerous lingerie and perverted toy sets inside one of the rooms. The promo video also briefly shows a woman being strapped to a table while being blindfolded inside the same house.  

According to Cartermatt, what makes the upcoming installment interesting through Gibbs' lens is that similar to himself, Roberts has been around the block and both of them are facing some of their own morality. They will have to come to terms with the idea that what they are doing will not last forever. 

Patrick Labyorteaux returns to "NCIS" for the first time since his appearance in the season 14 premier "Rogue." Previously, he has also appeared on the show for the second episode of its first season titled "Hung Out Dry." 

In the previous episode titled "High Tide," Bishop (Emily Wickershap) and Torres (Wilmer Valderrama) went undercover as a criminal couple for hire as part of an NCIS sting operation that aims to track down illegal drug-running in the civilian marina of Norfolk.

"NCIS" season 15 episode 12 will air on Tuesday, Jan. 9 at 8 p.m. EST on CBS.