"The Monster" - Pictured: Nia Long (Executive Assistant Director Shay Mosley). While investigating a missing personÕs case, the team uncovers a killer who puts on shows for high-paying voyeurs. Also, Mosley assigns Callen as her partner on a joint ATF mission to apprehend someone from her past, on NCIS: LOS ANGELES, Sunday, April 1 (9:00-10:00 PM, ET/PT) on the CBS Television Network. Photo: Monty Brinton/CBS ©2018 CBS Broadcasting, Inc. All Rights Reserved.

"The Monster" - Pictured: Chris O'Donnell (Special Agent G. Callen). While investigating a missing personÕs case, the team uncovers a killer who puts on shows for high-paying voyeurs. Also, Mosley assigns Callen as her partner on a joint ATF mission to apprehend someone from her past, on NCIS: LOS ANGELES, Sunday, April 1 (9:00-10:00 PM, ET/PT) on the CBS Television Network. Photo: Monty Brinton/CBS ©2018 CBS Broadcasting, Inc. All Rights Reserved.

"The Monster" - Pictured: RenŽe Felice Smith (Intelligence Analyst Nell Jones) and Nia Long (Executive Assistant Director Shay Mosley). While investigating a missing personÕs case, the team uncovers a killer who puts on shows for high-paying voyeurs. Also, Mosley assigns Callen as her partner on a joint ATF mission to apprehend someone from her past, on NCIS: LOS ANGELES, Sunday, April 1 (9:00-10:00 PM, ET/PT) on the CBS Television Network. Photo: Monty Brinton/CBS ©2018 CBS Broadcasting, Inc. All Rights Reserved.

"The Monster" - Pictured: Eric Christian Olsen (LAPD Liaison Marty Deeks). While investigating a missing personÕs case, the team uncovers a killer who puts on shows for high-paying voyeurs. Also, Mosley assigns Callen as her partner on a joint ATF mission to apprehend someone from her past, on NCIS: LOS ANGELES, Sunday, April 1 (9:00-10:00 PM, ET/PT) on the CBS Television Network. Photo: Ron P. Jaffe/CBS ©2018 CBS Broadcasting, Inc. All Rights Reserved.

"The Monster" - While investigating a missing personÕs case, the team uncovers a killer who puts on shows for high-paying voyeurs. Also, Mosley assigns Callen as her partner on a joint ATF mission to apprehend someone from her past, on NCIS: LOS ANGELES, Sunday, April 1 (9:00-10:00 PM, ET/PT) on the CBS Television Network. Photo: Ron P. Jaffe/CBS ©2018 CBS Broadcasting, Inc. All Rights Reserved.

"The Monster" - Pictured: Andrea Bordeaux (NCIS Special Agent Harley Hidoko) and Eric Christian Olsen (LAPD Liaison Marty Deeks). While investigating a missing personÕs case, the team uncovers a killer who puts on shows for high-paying voyeurs. Also, Mosley assigns Callen as her partner on a joint ATF mission to apprehend someone from her past, on NCIS: LOS ANGELES, Sunday, April 1 (9:00-10:00 PM, ET/PT) on the CBS Television Network. Photo: Ron P. Jaffe/CBS ©2018 CBS Broadcasting, Inc. All Rights Reserved.

"The Monster" - Pictured: Andrea Bordeaux (NCIS Special Agent Harley Hidoko) and Eric Christian Olsen (LAPD Liaison Marty Deeks). While investigating a missing personÕs case, the team uncovers a killer who puts on shows for high-paying voyeurs. Also, Mosley assigns Callen as her partner on a joint ATF mission to apprehend someone from her past, on NCIS: LOS ANGELES, Sunday, April 1 (9:00-10:00 PM, ET/PT) on the CBS Television Network. Photo: Ron P. Jaffe/CBS ©2018 CBS Broadcasting, Inc. All Rights Reserved.

"The Monster" - Pictured: Eric Christian Olsen (LAPD Liaison Marty Deeks). While investigating a missing personÕs case, the team uncovers a killer who puts on shows for high-paying voyeurs. Also, Mosley assigns Callen as her partner on a joint ATF mission to apprehend someone from her past, on NCIS: LOS ANGELES, Sunday, April 1 (9:00-10:00 PM, ET/PT) on the CBS Television Network. Photo: Ron P. Jaffe/CBS ©2018 CBS Broadcasting, Inc. All Rights Reserved.

"The Monster" - Pictured: Andrea Bordeaux (NCIS Special Agent Harley Hidoko). While investigating a missing personÕs case, the team uncovers a killer who puts on shows for high-paying voyeurs. Also, Mosley assigns Callen as her partner on a joint ATF mission to apprehend someone from her past, on NCIS: LOS ANGELES, Sunday, April 1 (9:00-10:00 PM, ET/PT) on the CBS Television Network. Photo: Ron P. Jaffe/CBS ©2018 CBS Broadcasting, Inc. All Rights Reserved.