Butterfly Effect (episode)

Butterfly Effect is the sixteenth episode of NCIS Season 20 and the 451st episode of the entire NCIS series.
==Synopsis==
When a potential biological terrorist attack occurs in the parking garage of a strip mall, NCIS investigate while Knight struggles as her father in Japan deals with a health scare.
==Prologue==
==Act One==
==Act Two==
==Act Three==
==Act Four==
==Act Five==
==Cast==
===Series Regulars===
Name 	Portrayed by 	Role
Timothy McGee 	Sean Murray 	Senior Agent for the NCIS Major Case Response Team.
Nicholas Torres	Wilmer Valderrama	Special Agent for the NCIS Major Case Response Team.
James Palmer 	Brian Dietzen 	Chief Medical Examiner for the NCIS Major Case Response Team.
Kasie Hines 	Diona Reasonover 	NCIS Forensic Specialist.
Jessica Knight 	Katrina Law 	NCIS Special Agent.
Donald Mallard 	David McCallum 	NCIS Historian. Despite being credited, McCallum doesn't appear in this episode.
Leon Vance 	Rocky Carroll 	NCIS Director.
Alden Parker 	Gary Cole 	Special Agent in Charge of the NCIS Major Case Response Team.
===Guest Cast===
Name 	Portrayed by 	Role
Dorothy Quinlan 	Julianne Collins	Phillip Legrand's daughter.
Phillip Legrand 	Greg Benson 	Dorothy Quinlan's father.
Constance Miller 	Brigid Brannagh 	Senator.
Nate Billings 	Sonny Valicenti 	Spy.
Boggs 	Tina Huang 	Navy Captain.
Martinez (Butterfly Effect)	Al Rodrigo 	MPD officer.
Sheehan 	Johnny Jay Lee 	Navy Petty Officer.
George Barlow 	Dominic Pace 	
William Jolson 	Jimmy Walker Jr.	Former Sergeant.
Cole (Butterfly Effect) 	Mircea Oprea 	Metro Police Department Officer. Uncredited role.
  v—[ e]—dNCIS Season 20
♦ A Family Matter (episode) ♦ Daddy Issues (episode) ♦ Unearth (episode) ♦ Leave No Trace (episode) ♦ Guardian (episode) ♦ The Good Fighter (episode) ♦ Love Lost (episode) ♦ Turkey Trot (episode) ♦ Higher Education (episode) ♦ Too Many Cooks (episode) ♦ Bridges (episode) ♦ Big Rig (episode) ♦ Evil Eye (episode) ♦ Old Wounds (episode) ♦ Unusual Suspects (episode) ♦ Butterfly Effect (episode) ♦ Stranger in a Strange Land (episode) ♦ Head Games (episode) ♦ In the Spotlight (episode) ♦ Second Opinion (episode) ♦ Kompromat (episode) ♦ Black Sky (episode)
Category:NCIS Episodes
Category:NCIS Season 20 Episodes
Category:NCIS Episodes written by Christopher J. Waild
Category:NCIS Episodes directed by Tawnia McKiernan