Grace Monroe paradoxically shuns artifice, despite wearing a mask of her own. Nine years ago, she stepped off the face of the Earth, and she hasn't looked back since. While Grace never chose a life on the Train, she revels in her quest to rescue children from the False Conductor's heresy. That is, until somebody else comes along... and leads Grace to a dangerous truth. Emily Wong prefers to hide stones with flowers, going so far as to sugarcoat cosmic horrors. She left Earth of her own volition, but a recent brush with death has left her torn between her pursuit of an idealized fantasy... and the harrowing reality of a conscious planet wanting her dead. In a universe where the events of Book 3 never came to pass, what becomes of Grace a year later, when someone neither denizen nor passenger decides to board the Train? ∞ "Replicator's Tide is a planet whose inhabitants, many millennia ago, created a new piece of technology. It is unknown why they created it or what they meant to accomplish through its creation, but we do know that the technology they created grew out of their control and absorbed the entire globe. What they created were self-replicating nanobots, and this is their planet." ~ Owen Dennis

"When you're stuck between two places, no one knows where you're coming from." After half a life spent on the tracks, Grace finally takes flight... only to find herself trapped in an egg (or, at least a spaceship that looks the part). Grace always thought her Exit would take her back home, and even though this new place is distinctly alien, it's the most "at-home" she's ever felt. Is her destination a layover, or a new beginning in disguise? Galactaron doesn't get many visitors, and Grace's arrival comes as a surprise to both parties. While the residents of the egg-ship welcome her with open arms, the tide effects of their most recent venture have only just begun to fester. Emily's keeping secrets again, and Grace finds herself caught between a prospective soulmate and her new alien friends. There's also the matter of the ship itself--don't think I'd let you forget! For the grieving world from which it alights isn't so ready to let it depart. Where some seek to forsake their pasts, others cling for dear life. The Replicators may have reconciled, but the same can't be said for the Conductor and Brakeman of tidal鐵道.

"I've always thought [the stars] were lighthouses. All they can do... is shine their lights from afar. They shine their lights at the other lighthouses, and at me. One day... I'm going to befriend one of them." ~ River (To the Moon, 2011)