Bitroux the metalsmith

What if the walls of the world were really open? when did it happen? when exactly did ahm's shield dissipate and how is it that merouac's sister was the first one to walk through? 'malaena came down to visit me about a shade before she passed, ' merouac told wemitte. he took a puff of his cigarette and pulled some tobacco from his lips. 'she told me that she had found a way to walk between the worlds.' 'oh, ' sighed wemitte. 'that poor woman.' 'she had started getting sick, by that time. i told her she needed to see a doctor. but she was so stubborn, so insistent. and then i asked her why she would even want to do it. what was beyond that was so wonderful she wanted to leave?' merouac is full of regret about the way he neglected his twin sister malaena. now she's gone and he's got his hands full taking care of her wilful and curious young daughter. faced with the ever increasing pressures of his job as head metalsmith on the transcontinental railroad, merouac struggles to keep up with his niece and doesn't always manage to keep her out of harm's way. but when evra is lured into danger by the ephemeral visages he thought only he could see, merouac is forced to consider the idea that the stories his sister told him as a child were true. as the ramifications of a world opened up beyond the shield break through the population, the mystery surrounding malaena's death deepens. has she really walked between the worlds like she said she would, and if she has, what does that mean for the rest of them?