Sam Gardner (Keir Gilchrist, “It Follows”) considers his family a pack. “For most mammalian species, survival depends on knowing and sticking with your pack,” he tells us in the trailer for “Atypical’s” second season. “But the members of my pack keep migrating.”

His father (Michael Rapaport, “Justified”) has left in the wake of his mother’s (Jennifer Jason Leigh) affair, and his younger sister (Brigette Lundy-Paine, “The Glass Castle”) has transferred to a different school. “It’s a mystery,” Sam concludes. “What was once something that seemed so rock solid — it cracks right open.”

On top of everything else, Sam, who is on the Autism spectrum, is contending with the prospect of major change: high school graduation. “I have no idea what I should do,” he admits to his sister.

“Atypical” is created by Robia Rashid. Season 1 centered around Sam’s efforts to find a girlfriend and establish some independence from his family. It was nominated for Best Television Series, Comedy or Musical at the 2017 Satellite Awards.

Rashid has previously written for and produced “The Goldbergs” and “How I Met Your Mother,” among other series.

“Atypical” returns on Netflix September 7.