Samantha Robertson is the eldest daughter of John Robertson and Alison Robertson. After the Combine's takeover she was transferred to City 14, where she ended up sharing an apartment with Nathan Johnson. Although Samantha was a lot more serious and was irritated by Nathan's foolishness, the pair of them became friends. When Nathan was smitten with her, he proposed in which she accepted.
After their wedding she was ran over and killed by her ex-boyfriend Derrick Thompson. Years later Nathan would avenge Samantha's death by killing him, which brought closure over the incident.
Samantha would continue to be referenced to in the series. Her sister Hannah Robertson appeared regularly and Nathan would look out for her. However just over five years after Samantha's death, Hannah was murdered by Frank Blackstone.
On the tenth anniversary of Samantha's death Nathan visited her graveside shortly after going on the run from a mysterious group. He admitted that even if she had lived on, things wouldn't have been truly happy as he was a terrible person who brings misery and destruction to those around him. After leaving her grave, a mysterious figure visits the graveside. The man voices disappointment at Nathan's actions, and reveals that he will never learn about a (currently unknown) truth pertaining to Samantha.
New World Timeline
In this alternative continuity to the primary City 17 Street universe, Samantha Robertson is still alive, still married to Nathan and they both have a son named Gareth. The family live in the town of New Haven, which is located nearby the ruined Black Mesa Research Facility.
When Nathan from the primary verse crosses over, he is surprised (and at the same time happy) that Samantha is still alive, although she finds his odd behaviour a mystery. When Nathan accuses Mayor Wallace Breen of being bad, Samantha is angry at his behaviour, not knowing who Breen was in the primary timeline. However Nathan's accusations are correct, as Mayor Wallace Breen has teamed up with his primary verse counterpart to build a Combine army and dominate the outer world.
Samantha kicks Nathan out of their home after being fed up with him. But unfortunately Mayor Breen sends his private guards to kidnap Gareth and when Samantha attempts to stop them she is attacked and stabbed and ends up hospitalized. While in hospital she is visited by the primary verse Breen, who gives her information on the multi-verse, and Nathan's terrible actions in the primary universe such as killing people and also kidnapping Samantha's younger sister Hannah at one point (missing out the fact he felt guilty and rescued her). This brings shock to Samantha and even though Nathan rescues Gareth and has Mayor Breen arrested, she doesn't want to be with him. Nathan accepts this and leaves New Haven, although she does tell him he can see Gareth anytime.
Two years later Samantha and Nathan are now divorced, with him living in Europe. Samantha grows depressed, especially after losing her job and she ends up moving in with her father, who unknown to her is the Elder Supreme.
City 17 Chronicles
Samantha appears in a re-imaging to City 17 Street. She features in the introduction of Volume 1 in which she is hiding out at a resistance complex in the countryside with her family. Nathan helps them to escape on a train when they are ambushed by the Combine, but at the expense of him being captured and sent to City 17.
- Samantha uses a modified Zoey model from Left 4 Dead.
- As the canon of City 14 was once up for consideration, there were plans to bring Samantha back in City 17 Street, thus ignoring her death in City 14. A planned series (acting as a sort of family sitcom) would have seen a married Samantha and Nathan with a son named Charlie and their lives in post-Combine City 17. A planned prequel story featuring the Robertson family was to also feature Samantha, but nothing more was done with the plot. Also when a second season of City 14 was planned, Samantha was to return and the first episode featured her being stabbed and her life on the line.
- Samantha features in the prequel/re-imagining series Black Mesa. Although taking place at least ten years prior to City 17 Street, she is depicted as the same age as she was in the main series.