Once an exile, Matthias returns to lead his home Enclave and settles into a new life with his beloved Solomon. Struggling with his new role and responsibilities toward the new town of Sanctuary and the people who had once rejected him, he knows that the relative peace he's found is temporary. Then tragedy strikes, sending Matthias, Solomon and Tam out once more, seeking answers in the forbidden north; answers that may lead to new beginnings, or to the end of everything they've ever known.