The 100 2×12 “Rubicon” – Tensions between Clarke (Eliza Taylor) and Abby (Paige Turco) come to a head after Clarke crosses the line. Raven (Lindsey Morgan) helps Bellamy (Bob Morley) navigate Mount Weather. Jaha (Isaiah Washington) and Murphy (guest star Richard Harmon) encounter a stranger who may not be what she seems. Octavia (Marie Avgeropoulos) is prepared to fight for someone she loves. Meanwhile, things reach a breaking point at Mount Weather. Christopher Larkin, Ricky Whittle and Henry Ian Cusick also star. Mairzee Almas directed the episode written by Aaron Ginsburg & Wade McIntyre (#212). Original air date 2/11/2015.