Sam is first seen standing beside his sister as their mother is in a video call with their father in Phase Six. Later, in a flashback at the start of We'll Get There, he is seen giving his father a photo of them standing together.
He is later seem again in Trials where he's helping his mother and sister around in the cabin. A short while later, he contracts the virus from his mother. His Grandfather then rushes the whole family in his car to Olympia in a desperate attempt to find help. They take refuge in Olympia where they are reunited with Tom Chandler. Unfortunately, his mother had fallen victim to the virus.
As Sam, Ashley, Jeter and Jed found shelter to hide From the Maryland State Troopers, Sam starts to not feel well and Ashley was starting to think his vaccine did not work but later realized that since he was more sick then Jed and Ashley he was just letting the sickness from the virus out of his body. He then resided in the vaccinated city of Norfolk with is sister and grandfather.
At the end of Season 3 in Don't Look Back, Sam & Ashley were kidnapped by Alison Shaw in an attempt to lure Tom Chandler out, but this attempt ended up back firing and Shaw was shot dead by Chandler.
He now resides in Greece with his father and sister as Tom sought to disappear with his kids to a quiet life.