Highlights from the Twelfth Episode of Season 4 of NCIS: LA

Pictured (L-R): Peter Cambor (Operational Psychologist Nate Getz), David Bickford and Linda Hunt (Henrietta "Hetty" Lange). A distraught widow is suspicious of the circumstances surrounding her Marine husband’s last battle and Sam and Callen help to determine if there has been a cover-up. Meanwhile, Hetty summons Operational Psychologist Nate Getz to be her “pawn." Photo: Monty Brinton/CBS ©2012 CBS Broadcasting, Inc. All Rights Reserved.

Pictured (L-R): David Bickford, Peter Cambor (Operational Psychologist Nate Getz) and Linda Hunt (Henrietta "Hetty" Lange). A distraught widow is suspicious of the circumstances surrounding her Marine husband’s last battle and Sam and Callen help to determine if there has been a cover-up. Meanwhile, Hetty summons Operational Psychologist Nate Getz to be her “pawn." Photo: Sonja Flemming/CBS ©2012 CBS Broadcasting, Inc. All Rights Reserved.

Pictured (L-R): Eric Christian Olsen (LAPD Liaison Marty Deeks) and Daniela Ruah (Special Agent Kensi Blye). A distraught widow is suspicious of the circumstances surrounding her Marine husband’s last battle and Sam and Callen help to determine if there has been a cover-up. Meanwhile, Hetty summons Operational Psychologist Nate Getz to be her “pawn” while the rest of the NCIS: LA team sense another evaluation on the horizon. Peter Cambor, a former series regular from the first season, returns to NCIS: LOS ANGELES to guest star as Operational Psychologist Nate Getz. Photo: Sonja Flemming/CBS ©2012 CBS Broadcasting, Inc. All Rights Reserved.

Pictured: Linda Hunt (Henrietta "Hetty" Lange). A distraught widow is suspicious of the circumstances surrounding her Marine husband’s last battle and Sam and Callen help to determine if there has been a cover-up. Meanwhile, Hetty summons Operational Psychologist Nate Getz to be her “pawn." Photo: Sonja Flemming/CBS ©2012 CBS Broadcasting, Inc. All Rights Reserved.

Pictured: Peter Cambor (Operational Psychologist Nate Getz). A distraught widow is suspicious of the circumstances surrounding her Marine husband’s last battle and Sam and Callen help to determine if there has been a cover-up. Meanwhile, Hetty summons Operational Psychologist Nate Getz to be her “pawn." Photo: Monty Brinton/CBS ©2012 CBS Broadcasting, Inc. All Rights Reserved.

Pictured: Chris O'Donnell (Special Agent G. Callen), LL COOL J (Special Agent Sam Hanna) and David Bickford. A distraught widow is suspicious of the circumstances surrounding her Marine husband’s last battle and Sam and Callen help to determine if there has been a cover-up. Meanwhile, Hetty summons Operational Psychologist Nate Getz to be her “pawn” while the rest of the NCIS: LA team sense another evaluation on the horizon. Photo: Monty Brinton/CBS ©2012 CBS Broadcasting, Inc. All Rights Reserved.