Doris McGarrett is a CIA agent codenamed "Shelburne" who is also the wife of John McGarrett and also the mother of Steve and Mary Ann McGarrett.
Doris was once an agent who worked for the CIA and who during her time as an active operative killed many people including Wo Fat's unnamed father.
At some point, Doris grew tired of her work and left the agency, eventually marrying John McGarrett and having two children: Lieutenant Commander Steve McGarrett and Mary McGarrett but the happy family life Doris had didn't last for long as her CIA life came back to haunt her with a vengeance.
To protect her family, Doris faked her death in a car bombing and spent the next twenty years in hiding with the help of Steve's C.O, Joe White.
In late 2011, Steve, now a Navy SEAL in the Reserves and the head of the Five-0 Task Force learned from Special Agent Kensi Blye about the name, "Shelburne" during the Season 2 episode, Ka Hakaka Maika'i (episode) and as such, Steve embarked on a mission to uncover the truth about "Shelburne" but Steve later discovered that he was not the only one searching for "Shelburne" as the team's enemy, Wo Fat was on the trail of Shelburne as well.
This culminated in Steve's eventual capture and torture at Wo Fat's hands during Kil'ilua (episode) although Steve was later saved by his 5-0 colleagues of Detective Danny Williams, Detective Chin Ho Kelly and Officer Kono Kalakaua as well as Agent Lori Weston, Joe himself and a Navy SEAL team led by Lieutenant Commander Wade Gutches.
Despite this, Steve's determination to find "Shelburne" did not dispel and he eventually left the 5-0 team during Ha'alele (episode) and the crossover episodes with NCIS: Los Angeles, Pa Make Loa (episode) and Touch of Death (episode) and headed to Japan to look for Wo Fat and Joe while leaving the 5-0 team in Danny's care.
After much searching, Steve found Wo Fat in Ua Hopu (episode) and after a stand-off with the Japanese Yakuza whose leader, Adam Noshimuri, Kono's boyfriend wanted Wo Fat dead for killing Adam's father, Hiro Noshimuri, Wo Fat was taken to prison.
In the Season 2 finale, Ua Hala (episode), confident that Wo Fat was behind bars, Joe brought Steve to a house in Suruga, Japan and told Steve he was sorry before disappearing. When Steve knocked on the door, he was reunited with his mother after nearly twenty years and realized that she was "Shelburne".
In the Season 3 premiere episode, La O Na Makuahine (episode), Doris revealed that she had been a CIA operative and had killed Wo Fat's father and she later left the agency to marry John McGarrett and have a family but when her CIA past returned, Doris had opted to fake her own death with Joe's help.
Steve later brought Doris back to Hawaii and was forced to call on his friend Lieutenant Catherine Rollins for help when Danny informed them that Wo Fat had escaped.
- In all her appearances, Christine Lahti has been credited as a Special Guest Star.
- Was seen wearing her watch on her right wrist during Popilikia (episode), suggesting that Doris might be left-handed.