A sick child appears while the team is investigating the island, but Sarah suspects something is amiss when the child is miraculously healed; Julia and Caleb make a discovery that furthers the mystery of the island when they dig up Alan's grave.
Michael struggles to keep the abbey under control as the CDC team move closer toward tracking the source of the pathogen; at the same time, Alan fights the urge to rejoin his former colleagues and comes to terms with the reality about Peter's allegiances. In the future, Walker takes a risk attempting to escape her delusional father.
In the Season 2 finale, Alan's relationship with Walker reaches a bloody climax, while his sibling feud with Peter erupts in flames. Elsewhere, Kyle does his best to protect a possible cure for the mycosis.