Despite being an assassin, Sam had a strong moral compass. Due to the death of his mother at the hands of a jealous a client, Sam was sympathetic to slaves and prostitutes, making him well-liked among Madame Clarisse's prostitutes, particularly Lysandra. Although he displayed kindness to the prostitutes, he never employed their services and even appeared to have an aversion to doing so. Likewise, Sam was extremely displeased when he learned of the slave trade deal Arobynn Hamel had made with Captain Rolfe; he became especially incensed upon discovering that their were children among the slaves that would be sent to Rifthold. This outrage compelled him to aid Aelin in her plot to free the slaves.
When Sam was a child, his mother, a prostitute, was murdered by a jealous client. Before her death, she had asked Arobynn Hamel, her lover, to take care of her son in case of her death. Sam became an assassin, one of Arobynn's best trainees, alongside Aelin Galathynius, whom he had known since childhood .
Sam first appears at the meeting in the Assassins' Keep at which Arobynn informs his inner circle that Gregori's mission was a trap. Sam sitting in Ben's seat irks Aelin. She tells the circle to kill Gregori, who is incarcerated in the royal dungeons, to keep him from revealing information. When Arobynn discloses Ben's death and Aelin demands to know why the Guild did not have his body, Sam jumps in, reasoning that the scene was full of guards and soldiers and that taking the body would lead the authorities to the Keep. 
Two months later, Sam and Aelin arrive at Skull's Bay, located on the Dead Islands, as emissaries for Arobynn to Captain Rolfe, Lord of Pirates. Sam expresses annoyance with Aelin's snooping around Rolfe's office, but she continues to do so and even sits in Rolfe's chair. Sam introduces himself before Aelin launches into a tirade against Rolfe in which she accuses him of being involved in the attack against the assassins. When Rolfe opens Arobynn's documents and reveals that the documents demand no retribution for the deaths of the assassins but rather is a slave trade agreement, Aelin immediately assumes that Sam knew about the contents of the documents but concealed the information from her anyway. Rolfe tells Sam and Aelin that there are two rooms prepared for them, and Sam chuckles when Rolfe misinterprets Aelin's reason for insisting that only one room is necessary.
Upon their arrival in their room, Aelin turns to Sam to berate him about the slave trade agreement, but Sam informs her that he didn't know anything either until Rolfe opened the documents. Aelin hypothesizes that Rolfe lied about the contents of the documents, but Sam points out that there was no reason for him to. He then asks if he can bathe first, causing Aelin to throw her cloak at him and declare that she will go first.
At dinner, Sam spends a great deal of time mocking Aelin. He listens with fascination as Rolfe recounts the story of his tattoo. Then he asks how Rolfe became the Pirate Lord; Rolfe replies that he killed every pirate better than he was, before advising Aelin to be leery around Sam, who chortles in response. When he and Aelin retire to their room for the night, Sam continues to lightheartedly tease her.
The following morning, Aelin half-jokingly asks if her breakfast is poisoned; Sam responds by inquiring whether she thinks the food was poisoned by him or by the pirates. Sam then presses her about her discussion with Rolfe earlier that morning, and he demands that she be honest with him when she dodges the question. In an attempt to evade answering Sam's questions about what she wants from Rolfe, Aelin suggests that perhaps she can't resist Rolfe's good looks, causing Sam to go tense. He opens the window because he is warm and frustrated with Aelin, but she shuts the window and the shutters before tossing his cloak over the window. Irritated, Sam tells Aelin that he tires of the melodrama revolving around Aelin's mask and cloak and of her bossing him around. Sam grips her wrist and reminds her that she still answers to Arobynn; Aelin threatens to cut his hand off if he touches her again.
They were punished by Arobynn after freeing the slaves and were separated for an entire summer when Aelin trained with the Silent Assassins in the Red Dessert. As to what Sam did during this period, it was not mentioned. They met once more after summer and tensions arose once again, in part purposefully by Lysandra, who at this point enjoys little more than getting under Aelin's skin.
At the end of The Assassin and the Underworld, Sam was able to profess his love for Aelin which she accepted and affirmed that the feeling was mutual. Aelin sold her Asterion mare to pay off Sam's debt to Arobynn. Aelin had bought an apartment two days after her beating in which she lived with Sam up until The Assassin and the Empire.
They planned on leaving the continent to start a new life together but were unable to execute this dream due to Sam's tragic death which led to Aelin's utter heartbreak, capture and sentence to the Salt Mines of Endovier.
Aelin initially despises Sam, but Sam, despite his prickly attitude toward her, is secretly in love with her. During their trip to Skull's Bay together, they grow closer. Sam even suggests that he and Aelin run away together to escape Arobynn's wrath for freeing the slaves, much to Aelin's shock. They share a few intimate moments. They successfully execute their plan, and by the end of The Assassin and the Pirate Lord, they have become friends.
When they return to the Assassins' Keep, Arobynn orders Tern and Mullin to restrain Sam. Aelin internally panics because she believes that Arobynn is going to make Harding beat Sam and force her to watch; instead, Sam is forced to watch Aelin get beaten, because Arobynn knows that Sam loves her and that this is the most effective way to punish him. Through the entire bludgeoning, he struggles and screams at Arobynn, "I'll kill you!" As Aelin fades out of consciousness, she expresses relief that Arobynn has not hurt Sam. After Aelin falls unconscious, Arobynn has Sam beaten as well.
During her stay in the Silent Assassins' fortress, Aelin attracts the attentions of Ilias, the Mute Master's son. Aelin remarks that Ilias is desirable—perhaps even as desirable as Sam—and thinks how she never expected that she'd call Sam desirable. Although she thinks Ilias is handsome and sweet, Aelin gently rejects him when he attempts to kiss her; she explains that they live too far apart, but inside she knows that the real reason she turned him down is because when Ilias tried to kiss her, all she could think of was Sam.
Upon returning to Rifthold, Aelin reunites with Sam. He inquires about the Red Desert and expresses concern for her when he spots the scar Ansel gave her. After her experience with Ansel, Aelin is initially hesitant to trust him, but she recalls the night she was beaten and realizes that Sam would stand by her and that he is trustworthy; she also reminds herself that Sam has had plenty of chances to harm her, but he hasn't taken them. Her jealousy spikes when she notices how much attention Lysandra is giving him, and she frets that Lysandra and Sam might be involved, even though Sam insists that they are not. Aelin eventually feels guilty for saying such rude things to him.
Arobynn hires a Melisande tinkerer to make specialized suits for Sam and Aelin. He will give Aelin her suit for free, but he will make Sam pay for his suit. When Arobynn leaves the room, Aelin requests that the tinkerer incorporate Spidersilk cloth she received from a merchant in Xandria, telling him to use it to protect the heart. It is later revealed that Aelin commissioned this for Sam's suit, not hers, and paid for his suit.
At the concert, Sam compliments her appearance, and she returns the gesture; they reconcile. When Lysandra mocks Aelin for weeping over the splendor of the performance, Sam jumps to Aelin's defence and snaps at Lysandra to shut up.
While Aelin tries to replicate the music on the pianoforte, Sam walks in. She bristles when she hears that he spent time with Lysandra after the concert, but Sam maintains that he doesn't have romantic feelings for Lysandra and points out that Lysandra did not choose to be a prostitute. Sam explains that his punishment for their escapade in Skull's Bay was to watch Aelin be beaten; when she asks why, he says that after Skull's Bay, she should know why. Aelin demands whether he will make a bid for Lysandra, but Sam points out that even if he wanted to, he has no money. He teases Aelin about being afraid that he and Lysandra had had a summer romance. To get back at him, Aelin mentions Ilias, which drains Sam of his jovial mood. She immediately regrets saying this, and she solicits his help with her contract on Benzo Doneval, offering him half of the pay. Sam refuses to take the money, saying that ruining another slave trade agreement is reward enough.
While at Leighfer Bardingale's party, Sam helps Aelin collect intel on Doneval and his business partner. When a masked man flirts with an intoxicated Aelin, Sam defensively interrupts, informing the interloper that she is spoken for. His protectiveness irritates Aelin, who then suggests that he should be with Lysandra or another courtesan. Sam insists that he does not want to be with courtesans and that she is a fool for not seeing that, and that he cares enough to be at the "disgusting party" just to be with her. Aelin makes a clumsy attempt at an apology and tells him that her anger at him isn't about the masked stranger and not dancing with him. Sam smiles and tells her that they can discuss it tomorrow.
- In Queen of Glass, his name was Symeth.