We survived a decade in this hellscape! You have no idea what we went through, what we sacrificed for this. And now the people responsible are upstairs. We could finish it, but you want to kill me
~ Voss speaking to Deke Shaw
Samuel Voss was a major antagonist in Season Five of Marvel's Agents of S.H.I.E.L.D. He is a member of the true believers who was friends with Leo Fitz's Son In Law, although he killed his former friend when the agents of S.H.I.E.L.D arrived.
Some time before 2091, Voss became acquainted with Owen Shaw and was a friend of his. Voss joined the true believers, a group of people living at the lighthouse who belived that S.H.I.E.L.D would return to save them. However the Kree soon discovered these beliefs and dissaproved of them, so Voss was sent to the surface to be eaten by the Vrellnexians, however he survived up there along with Shaw.
It soon turned out that Voss and Shaw had diverging opinions regarding how the True Believers should cooperate with the S.H.I.E.L.D. agents. Indeed, Voss was in favor of killing Daisy Johnson, who was considered responsible for the destruction of the planet. This led to an argument between Voss and Shaw, who threatened Voss with a knife. Voss defended himself and eventually stabbed his best friend to death.
A decade from the moment Robin Hinton prophesied for the S.H.I.E.L.D. agents to make it to the surface of the Earth from the Lighthouse. Voss asked a group of True Believers to pick them up and take them back to the Zephyr One, where he had already welcomed Melinda May and Enoch. Upon recognizing his late best friends son Deke Shaw, Voss cheerfully greeted him and lied to him, saying that Owen would soon be back on the plane as well and assured Deke that the family reunion would go well.
Voss later told Leo Fitz and Jemma Simmons about the machine that was designed by Owen to use the White Monolith and take the S.H.I.E.L.D. agents from the past. He then left them on their own and took Agents Coulson and May to the armory as he planned an assault against the Kree. When May found a shard of the White Monolith, Voss explained that it was the only piece he had found and that they should focus on more concrete plans like attacking the Lighthouse.
Voss was later confronted by Deke Shaw, who questioned him about the White Monolith's shard, claiming that his father would never have left the shard behind as he always kept it on him. Voss realised that Deke had understood that he had lied about Owen. Deke asked him what had happened to his father, Voss, seeing no alternative punched him and knocked him out, locking him in a cell.
Voss went to see Daisy Johnson, who failed in getting some answers from Robin Hinton. He took her to a computer and showed her a video of herself on Earth moments before she destroyed the planet, explaining that this was the evidence that Quake had caused the end. As such, Voss revealed his plan and his true colours: attempting to kill Quake so she could not return to her time and crack the Earth apart.
Voss and a group of his men attacked Johnson who, despite being deprived of her powers, managed to fight off their assaults. As Robin approached the fight, Voss decided that he could not let her give them answers which could help them to go back into their time. Therefore, Voss stabbed Robin in the stomach. Voss then attacked Daisy again, but he was eventually stopped by Daisy and Coulson. As Voss watched the death of Hinton, he warned Daisy to remember this moment and that he tried to stop her.
Voss was locked up in Zephyr One and was soon visited by Deke, who had a weapon in his hand. Although Voss explained that he understood why Shaw wanted to kill him for the murder of his father, he urged Shaw to reconsider and play on the long game, which meant siding with him against the time travelling S.H.I.E.L.D. agents and let Kasius have the Destroyer of Worlds. Shaw left silenty, choosing to spare his prisoner for the moment.
As the S.H.I.E.L.D. agents planned to take the Zephyr One back to the Lighthouse, Phil Coulson came to Voss' cell to set him free and let him join the caves with the other True Believers. Before departing, Voss warned Coulson about the consequences of their actions, stating that they would cause the Destruction of Earth. Voss then left the plane to hide from an incoming gravity storm.