The 100 is all new tomorrow night with the first part of its season finale, titled We Are Grounders. In 51 hours, life on the Ark will cease to exist.

Watch a preview with EP Jason Rothenberg and Supervising Producer Dean White.

Plot summary – SHOULD WE STAY OR SHOULD WE GO — Clarke (Eliza Taylor) and Finn (Thomas McDonell) escape one dangerous situation only to find themselves faced with a new enemy. Bellamy (Bob Morley) makes a heroic move to save Jasper (Devon Bostick). Raven (Lindsey Morgan) faces a new danger, and Murphy (guest star Richard Harmon, “Bates Motel”) finally gets his revenge. Meanwhile, those remaining on the Ark are coming to terms with the inevitable. Paige Turco, Isaiah Washington, Henry Ian Cusick, Marie Avgeropoulos and Chris Larkin also star. Dean White directed the episode written by Tracy Bellomo & Akela Cooper (#112).