Bellamy and Octavia's background story is revealed when 17 years ago on the Ark, Octavia is born (against the one-child-only policy on the Ark) and her mother tells Bellamy that he will be his sister's keeper. Some years later, a "random" inspection is conducted in which Octavia is almost discovered. One year before the present, Bellamy takes Octavia out for the first time in her life to go to a dance, but a solar flare forces the Ark's police force to ID everyone present, leading to Octavia's discovery. Ten days ago, Bellamy's mother has been floated for a year and Octavia has been in lockup. Bellamy himself is approached by Commander Shumway to assassinate Jaha in exchange for a seat on the dropship. In the present, Bellamy searches camp for Octavia to no success. The 100 see a "meteor shower", but Clarke realizes it is actually bodies being floated from the ark. Bellamy assembles a group to take into the woods to find Octavia, meanwhile Clarke and Raven set out for Finn's bunker in hopes of finding a radio transmitter to contact the Ark with. Octavia has been abducted by a presumably-rogue grounder who has helped her rather than hurt her. Octavia escapes anyway, only to be later recovered by him. The hunting party is pursued by a band of grounders who kill three people from Bellamy's group. Clarke and Raven make it to the bunker and find a transmitter, and Raven manages to work out that Clarke and Finn had been involved. At camp, Raven confronts Clarke about this. In the forest, Octavia's grounder tricks the other grounders into thinking there is an acid storm coming, saving Bellamy and his group. Bellamy, Finn, Jasper, and others follow him back to his hideout and rescue Octavia, although Finn is stabbed in the confrontation. Not everyone makes it back to camp, but Clarke tells Raven she needs the radio (to talk to her mom) to save Finn, and Octavia blames Bellamy for everything that happened to her and their mother. Bellamy gets everyone who survived the search for Octavia, into camp as a fast-moving, deadly-looking thunder storm breaks.

Other Connections and Related Pop Culture

The 100 Season 1

# Title Air Date
The 100
1:1 Pilot Mar 19, 2014
1:2 Earth Skills Mar 26, 2014
1:3 Earth Kills Apr 2, 2014
1:4 Murphy's Law Apr 9, 2014
1:5 Twilight's Last Gleaming Apr 16, 2014
1:6 His Sister's Keeper Apr 23, 2014
1:7 Contents Under Pressure Apr 30, 2014
1:8 Day Trip May 7, 2014
1:9 Unity Day May 14, 2014
1:10 I Am Become Death May 21, 2014
1:11 The Calm May 28, 2014
1:12 We Are Grounders, Part 1 Jun 4, 2014
1:13 We Are Grounders, Part 2 Jun 11, 2014