For source of the info above, please check my Deviantart (DA) version for the links.
Thus, this artwork is my own imaginary scenario when Cassia finally learn the truth and Clove desperately try to explain things to her pissed-off sister and do anything to comfort her. But it's all in vain and Cassia eventually escape from the Northamer Egg Army base after this event.
Nevertheless, although this event will also appear in my "Post-Archie AU" as well but the outcome will be very different due to one particular and important factor in the storyline. You can check some of details from my DA site.