Picking up where Season 3 left off, we find McGarrett and Wo Fat cornered by unknown assailants in a detainment facility in season 4 of Hawaii Five-0, forcing McGarrett to break the law and turn on his own in order to find a kidnapped Catherine. Meanwhile Kono and Adam's secret location in Hong Kong is compromised, and Kono and Adam fight to stay alive when their hidden location is discovered.
All episodes — Season 4
S4 E1Aloha Ke Kahi I Ke Kahi (We Need Each Another)
Sep 27, 20137.643 min
After McGarrett and Wo Fat narrowly escape from maximum security, gunmen storm Five-0 headquarters, compromising Kono and Adam's secret location in Hong Kong and forcing McGarrett to break the law and turn on his own in order to find a kidn
S4 E2A‘ale Ma‘a Wau (Fish Out of Water)
Oct 4, 20137.844 min
As the Five-0 team members investigate a murder, they are led to a Texas ranger who came to Hawaii to look for his daughter; Adam and Kono fight to stay alive.
S4 E3Ka ʻoiaʻiʻo ma loko (The Truth Within)
Oct 11, 20137.944 min
A conspiracy theorist helps Five-0 when a missing artifact is the key to solving a double murder.
S4 E4A Ia La Aku (From This Day Forward)
Oct 18, 20137.844 min
Five-0 investigates the murder of a wedding crasher, and their prime suspect is the runaway bride. Meanwhile, Danny makes a big decision regarding his relationship with Gabby.
S4 E5Kupu‘eu (Fallen Hero)
Oct 25, 20136.844 min
As Catherine’s seemingly harmless surveillance job takes a deadly turn, Adam considers making the ultimate sacrifice to save Kono.
S4 E6Kupouli ‘La (Broken)
Nov 1, 20137.944 min
When Halloween comes to Hawaii and a zombie-like man is shot, Five-0 races to stop a madman who is conducting experiments on humans.
S4 E7Ua Nalohia (In Deep)
Nov 8, 20137.944 min
While working the murder case of an undercover ATF agent, McGarrett and the Five-0 team are tasked with watching Mary’s newly adopted baby after she gets sick.
S4 E8Akanahe (Reluctant Partners)
Nov 15, 20137.843 min
McGarrett and Grover must work together to protect national security after they are tasked by the Governor to serve a warrant to a young computer hacker.
S4 E9Hau‘oli La Ho‘omaika‘i (Happy Thanksgiving)
Nov 22, 20137.544 min
As Thanksgiving approaches, Five-0 investigates the murder of a secret service agent just as the President travels to Oahu. Also, McGarrett's Aunt Deb visits, bringing with her a shocking secret.
S4 E10Ho‘onani Makuakane (Honor Thy Father)
Dec 13, 2013845 min
The attempted murder of a Pearl Harbor veteran leads Five-0 to use decades old evidence to investigate a deadly crime committed within the internment camps on Oahu during World War II.
S4 E11Pukana (Keepsake)
Dec 20, 20137.544 min
An investigation involving a potential serial killer puts Chin's life in danger; Grace and Danny find a mysterious puzzle box.
S4 E12O Kela Me Keia Manawa (Now and Then)
Jan 10, 20147.544 min
Captain Grover is aided by McGarrett in his search for a friend who has disappeared, after it seems like he's committed murder. Kono persists in her quest to find Adam.
S4 E13Hana Lokomaika‘i (The Favor)
Jan 17, 20147.442 min
Chin is questioned about his father's murder and how his relationship with Malia and her family could have adversely affected the investigation.
S4 E14Na hala a ka makua (Sins of the Father)
Jan 31, 20148.144 min
An escaped convict who wants Five-0 to prove his innocence abducts Danny and McGarrett; Grace punches a person at school.
S4 E15Pale'la (Buried Secrets)
Feb 28, 20147.444 min
A real estate agent is found dead inside the walls of one of his listings. Meanwhile, Danny's mother makes an unexpected visit and brings with her some shocking news.
S4 E16Hoku Welowelo (Fire in the Sky)
Mar 7, 20147.543 min
A triple homicide is linked to a secret, downed Chinese satellite; Danny's mother goes on a ride-along with Grover.
S4 E17Ma Lalo o ka ʻlli (Beneath the Surface)
Mar 14, 20147.643 min
A man is shot as his daughter is abducted; Danny tries to reunite his parents; Jerry finds a code on McGarrett's champ box.
S4 E18Ho‘i Hou (Reunited)
Apr 4, 20147.544 min
Fan-built Episode. Five-0 investigates when the daughter of a macadamia nut tycoon is murdered with a stiletto heel during Chin’s high school reunion.
S4 E19Ku I Ka Pili Koko (Blood Brothers)
Apr 11, 20147.744 min
Five-0 is set up when a bad tip leads them to an abandoned building that is rigged to explode with McGarrett and Danny trapped inside.
S4 E20Pe‘epe‘e Kānaka (Those Among Us)
Apr 25, 20147.142 min
The investigation of a murdered pool cleaner leads the Five-0 team to a possible terrorist cell of radicalized students plotting an attack on U.S. soil.
S4 E21Makani ʻOlu a Holo Malie (Fair Winds and Following Seas)
May 2, 20147.244 min
McGarrett and Catherine travel overseas to Afghanistan to stop the Taliban from harming a young boy whose family saved Catherine's life years ago.
S4 E22O ka Pili ‘Ohana Ka ‘Oi (Family Comes First)
May 9, 20147.743 min
When Grover's daughter is kidnapped by an old nemesis, he is forced to help steal $100 million in order to get her back. Meanwhile, Wo Fat escapes prison and heads back to Oahu.