When she's seven years old, Rachel Sarah Weintraub will be dubbed by the media the "Virgin Victim of the Time Tombs' Curse" (4.505). But that's only after she graduates college and travels to Hyperion as part of her graduate dissertation.
No, she's not a child prodigy (that would make her love affair with one of her professors, Dr. Melio Arundez, exponentially creepier). Inside Hyperion's Sphinx, one of the mysterious Time Tombs, Rachel gets cursed with Merlin's sickness and starts aging backwards.
Each night, her memories reset. At first, she plays a tape back to herself, one she recorded where she explains the situation. It's all very Memento or Before I Sleep. Eventually the pain and anguish become too much, and Rachel just goes through every day like she's living it for the first time. Eventually she no longer debates religious philosophy with her father. Instead, she's going to elementary school.
As she gets smaller and smaller, Sol and Sarai adjust their routines to what they were when Rachel was that age: playing with friends at 7, learning to read at 5. Sure, "Rachel was one of those rare children who managed to be cute without becoming self-consciously precious" (4.150) and "friends said that the child combined the best portions of Sarai's sensitivity and Sol's intellect" (4.150), but going through it a second time isn't something her parents really wanted, and not just because they never wanted to change diapers again.
Rachel is just a few days old when Hyperion ends, and we're anxious to discover what happens when this fateful birthday arrives. She's condemned to be the innocent, as odd as that sounds. God wanted Abraham to sacrifice Isaac, which ol' Abe fully planned to do. Now that Sol plans to the do the same, will God (or something else) step in to save Rachel?
So now we're asking ourselves—what's the point? Is Rachel just here to be a lesson to her doubting, scientific father? Or does she have a character arc of her own—and not one that has her ending up as a zygote?