Bellamy and Octavia is the relationship between siblings Bellamy Blake and Octavia Blake. They are portrayed by starring cast members Bob Morley and Marie Avgeropoulos and debut in the series premiere. Because of the one child law on the Ark, Bellamy and Octavia are the only known siblings among the Sky People. They are half-siblings. Ever since Bellamy sided with Pike in Season Three, their relationship has been strained. After Lincoln's death, in Stealing Fire, Octavia disowned Bellamy, blaming him for Lincoln's death.