When Snowpiercer season 2 begins, and Wilford (Sean Bean) takes Melanie prisoner, we find out how she survived abandonment in Chicago seven years ago.
In the Ark story, we know that Wilford hired Melanie for her vision of engineering her, turning her train into something that could sustain her life. Yet as much as Wilford loved the rich alone, Melanie knew she needed all the classes.
Furthermore, she could not tolerate the chaos and potential dangers, which ironically included Wilford, a lover of sex and alcohol. She therefore left him at the starting point, as well as some of her loyalists, sadly sacrificing her daughter, Alexandra.
But since Wilford is holding her hostage in the Snowpiercer series, she admits that it took a lot of patience and stamina not to give up hope. And also, he’s taking a long time not to kill her now that he stole her role as her messiah of the new world.
Melanie is confused as to how they stayed low all this time, however, and Wilford admits that it took him some time to adapt Big Alice in 40 cars, as she was the initial Snowpiercer prototype.
They waited, but they had to head quickly with their perpetual motor because, without movement, they would die in the frozen world. It seems your mad scientists helped hide the ark by playing with other signs to make them invisible.
Also, the Headwoods have been making chemicals, medicines, and all kinds of things they need to survive, including super soldiers. That said, when Big Alice tried to catch up with Snowpiercer, they found it difficult.
Wilford had to just wait. It was a cat and mouse game in Snowpiercer, and while Melanie had most of the supplies, they got by with whatever resources they had. Wilford went from being driven by ambition to anger, risking Big Alice on dangerous routes.