Warning: This episode contains spoilers for Snowpiercer Season 2, Episode 2, "A Great Odyssey."
At the end of Snowpiercer's first season, during the invasion of Big Alice, Melanie Cavill went outside to try and detach the locomotive from Snowpiercer, but instead sealed the trains together. This in turn made any threats by Wilford towards her crew backfire onto Big Alice as well. While Melanie was outside, she made an impossible discovery — it was snowing. This meant that the world was warming up, and life on Earth could restart much earlier than previously predicted. However, in order to properly research any possible warming, Melanie appointed herself to spend a month outside of the train in a research station, and in order to get to there, Snowpiercer had to take on its most dangerous track yet.
To get to the facility, the train had to redirect its track onto the old Rocky Mountain test track, nicknamed Neckbreaker. While Big Alice successfully made it through Neckbreaker on its side passage, Alex doubts Snowpiercer's ability to make it up the mountain. Yet, Wilford is confident that with Big Alice's assistance, Snowpiercer can achieve the appropriate speed to make it through the mountain safely. Failure to get past the mountain would result in the train having to make a full revolution. It will need to try to mount Neckbreaker again from the other side, but by then, it might be too late, considering the environment changing at rapid pace.
Meanwhile on Big Alice, Wilford and Alex are making sure Melanie's expedition goes according to plan, as her absence allows the villain to take on Layton without her protection. With Layton still fresh from the revolution and struggling with order on the train and the return of Josie, it's the perfect time for Wilford to strike. Ben mentions that Wilford's true desire is power, so this is the best chance he has to take what he believes to be rightfully his.
With the weakened state of Snowpiercer, Melanie and the crew discover that they do not have enough power to make it through the mountain. To solve the issue, they would need to cut the power from most of the cars to give them the kick they need. After gathering all the passengers in first and second to the Night Car and third to Eg-Sec or Mess Hall, ensuring the safety of the passengers, Melanie cut the power, giving Snowpiercer enough strength to get onto the curve. Big Alice, driven by Alex, gave the train the extra boost it needed to get it through the Berthound Curve. With Snowpiercer curving onto the mountain, fighting the best it can to avoid derailment and make it safely, Alex heard her mother's advice; she felt the train, successfully getting Snowpiercer over Neckbreaker and guaranteeing a month without her recently reunited mother.
On the positive end, this also gave Melanie the perfect opportunity to study the changes. As the train comes to a stop, Melanie and Alex share a moment. They both wished they could have spent more time together, but Melanie is doing this mission for her daughter, ensuring she could live in a world without Wilford's influence.
Snowpiercer stars Jennifer Connelly, Daveed Diggs, Alison Wright, Mickey Sumner, Susan Park, Iddo Goldberg, Katie McGuinness, Lena Hall, Annalise Basso, Sam Otto, Roberto Urbina, Sheila Vand and Jaylin Fletcher. The series airs on Mondays at 9pm ET/PT on TNT.