Snowpiercer gets back on track with Melanie's return

After not appearing in five episodes, Melanie Cavill finally returns in "A Moth to a Flame," and it is the return that gets the story moving again. After several episodes of stunted pacing, bringing Melanie back to the compound encourages the necessity for the story to move on from the underground science labs and military station to move toward the promise of heating the world back up. "A Moth to a Flame" is also an episode that revels in preparing for the show's big finale by setting up plot twists and concluding storylines that kickstarted this journey in the first place.

Layton finally reunites with his daughter, which has been his main motivation throughout the season. Alex and Melanie also reunite after months apart which also works as a plot to update the other on their scientific findings and Ben's fate.

Otherwise, Snowpiercer starts to put its final plot threads together as it prepares for the final three episodes. Admiral Milius, who had been season four's main villain, meets a fairly quick and somewhat anti-climactic end at the conclusion of an episode that finally offers some details about his backstory and how he came to be in charge. But, Admiral Milius is not the only character to die.

After seasons of power struggles, unlikely alliances, and betrayals, Mr. Wilford dies in a final exchange with Layton where not only does Mr. Wilford die on his own terms, he gifts Layton the information he needs for the potential destruction of the world that is about to come, and how the events that are unfolding now are a direct result of how the Earth froze years ago in the first place.

In the end, it is a story of pride, ego, and the refusal to accept reality as Snowpiercer's final season plays its biggest villain card by revealing that the submissive scientist Nima was not only responsible for freezing the Earth a decade previously, but his wrong scientific calculations would also be responsible for killing the Earth a second time.

Nima's reveal as the season's main villain allows his conflicting views with Melanie and Alex's scientific findings to become a significant question about what will become of the Earth, especially if Nima refuses to listen when Melanie tells Nima that the plans he wants to implement will only make everything worse.

Considering "A Moth to a Flame" concludes with Layton, Josie, and Liana separated from the rest of Snowpiercer, Layton getting this information to those who need it may not be at the top of the list of priorities, especially if Layton will be forced to strive to survive the freezing temperatures.

Still, there is always a chance that Alex could unravel the mystery. With Melanie also sidelined again after Nima ensured her becoming unconscious for at least a few days, it might be up to Alex to stop Nima depending on how long it takes for Alex to reunite with Layton, Melanie, or Ruth.

Snowpiercer even sets up a cliffhanger for Ruth, Till, and Javi, as the episode's final moments see an explosion near by where Javi was standing. Although the audience is left uncertain of if anyone was actually affected by the explosion, it did slow down Ruth and Till's decision to walk to New Eden.

With only three episodes left, "A Moth to a Flame" has gotten the ball rolling in rising the stakes for the characters and the Earth. Snowpiercer needs to keep the momentum going as it charges toward the finish line.