Samantha "Sam" Taggart is a fictional character on the NBC television drama ER. She is played by actress Linda Cardellini. Linda Cardellini's addition into the main cast opening credits was in the fifth episode of season 10.
Precursor
Sam is a nurse and single mother; she has a son, Alex (played first by Oliver Davis, later by Dominic Janes). Alex was born when she was fifteen; she has had to raise him mostly on her own. She comes from a family of alcoholics; her anger toward Abby Lockhart in Season 14 when Abby tells the staff she had a relapse while working is explained when she tells Abby that she came from a long line of drunks who never tried to stop drinking.
Life at County and career
Viewers first meet Sam in the Season 10 episode "Out of Africa," where she distinguishes herself by quickly and effectively giving an intravenous sedative to an unruly patient, even impressing the usually stubborn Dr. Romano. Sam shows herself to be an assertive, experienced, and talented nurse throughout the episode, though she loses her professionalism a bit when she discovers Dr. Luka Kovač's unknowing part in her son Alex's diabetic fit while he befriends the boy. She replaces Abby Lockhart who was head nurse, but decided to become a doctor instead. Her no nonsense attitude had gotten her in trouble early on. In the episode "Death and Taxes", she took Dr. Robert Romano's mechanical hand after the ER Chief touched her inappropriately with the device. In addition, in the episode "Impulse Control", she punches an assault victim's abusive boyfriend in the face when he threatens her as she tries to call the police, but overcomes Dr. Kerry Weaver's knee-jerk lack of support and helps the abuse victim follow through on pressing charges.
Sam soon notices a bond between Alex and Luka. Though initially uncomfortable with Luka's involvement with Alex, Sam eventually accepts it and becomes good friends with Luka. Later, a romantic relationship develops. Unexpectedly, Alex's father, Steve (played by Cole Hauser), returns and attempts to push Luka out of their lives. When she discovers Steve might stay permanently, Sam panics, packs up, and runs away. Before doing so, however, Luka runs to her, trying to get information from her as to why was she is doing this. Ignoring him and his slams on the car, fighting tears, she drives away. Sam has had a history of picking up and moving around the country to escape Steve. She worries that he will ruin her and Alex's life and that they cannot coexist with Steve.
She does come back thanks to Luka who finds her at a motel and brings her back. They move in together. Throughout season 11, Sam and Luka lived together, and Luka was a surrogate father for Alex, even going and meeting with a school official after Alex got caught with an issue of MAXIM magazine. At the end of season 11, Alex runs away to find Steve (now played by Garret Dillahunt), by hitchhiking after a confrontation with Sam. He is out to find Steve in Colorado, even though Sam has hidden the fact Steve is there because he is in jail on robbery charges. Luka and Sam are frantically searching for him in the opener of season 12. Sam is desperately worried about Alex because of his diabetes, and his lack of insulin could have resulted in a coma or even death. Sam immediately gets in the car and drives non-stop to Colorado. Luka worries about Sam because they have been driving non-stop, and even hit a deer which completely destroys the windshield. Sam and Luka finally find an exhausted but stable Alex at a Canyon City hospital, where he claims he's okay and that he knows how to take care of himself. At this point, Sam realizes her relationship with Luka is not going to work; her personal life is too hectic for him to deal with, the two of them have communication problems, and Luka's special bond with Alex has been eclipsed by Alex's knowledge that his father is in jail. Sam breaks up with Luka awkwardly near the beginning of Season 12. Several episodes later, though, they appear to be friends again.
She met and immediately befriended Dr. John Carter upon his return from Africa, happy to "put a face to the name".
Later in season 12, a wealthy patient named Richard Elliot (played by Armand Assante) enters the ER. He has a debilitating disease and needs an in-home nurse. He takes a liking to Sam and offers her a well-paid position as head nurse. He assures her that she would still be able to keep her job in the ER, and invites her and Alex to live in a section of his mansion for convenience. She denies at first, but upon discovering that Alex cannot be in the tutoring program due to lack of funds, she visits Elliot's home and asks if the offer still stands.