The episode picks up immediately after the destruction of the Hosnian system.
In a massive reveal, the Colossus is revealed to be a giant starship rather than just a stationary platform. It launches from the water of Castilon into space to escape the First Order. [S1E19] No Escape Part 2
Kazuda Xiono watches in horror as Starkiller Base destroys his homeworld, Hosnian Prime, presumably killing his family and friends. The episode picks up immediately after the destruction