Barney persuades Ted to travel with him on the `drunk train', the last train at night from Manhattan to Long Island, where there are many opportunities to pick up women. However, Ted soon realises that Barney's conspicuous lack of success with the ladies indicates that he actually has genuine feelings for Quinn, a girl he recently dated.
Having discovered that Jasper may still be alive, Clarke, Bellamy, Octavia, Finn and Monty set out on a mission to locate their friend and are shocked at what they find. Meanwhile, on the Ark, Abby is determined to get to Earth, and enlists Raven (guest star Lindsey Morgan) to craft an escape pod.
Clarke’s newfound romance with Finn is threatened. After suffering a blow to the head, Octavia wakes up to find a Grounder watching her. On the Ark, Abby exposes Kane’s plan to reduce the population of the Ark. Then Chancellor Jaha and Abby notice a signal and realize at least some of the 100 must still be alive on Earth.
Bellamy leads his crew into Grounder territory as they search for Octavia. Raven can’t help but notice the deep connection between Finn and Clarke. Meanwhile, flashbacks reveal Bellamy and Octavia’s difficult childhood on the Ark.
Picking up where the season one finale ended, Clarke is still alone in the white room, frantically trying to make sense of her bizarre surroundings, while the fate of Bellamy, Finn and Raven is still unknown. Lincoln and Octavia’s daring plan is thwarted and an enemy returns. Meanwhile, Abby, Kane and the survivors of the Ark must face physical and moral dilemmas in their dangerous and beautiful new world. Finally, Jaha makes a heroic decision
