For returning readers:
Rewrite now includes the solution to Isaac Newton's problem in chapter 14, orphanage scenes, and Hermione's backstory. On hiatus for the school year.
In the crater where the Department of Mysteries used to be, she paused amidst the rubble. The stone arch still stood. It had been oblivious to the many battles that had been held at the Ministry, absorbing any spell, object, or person thrown at it.
Hermione often wondered about the Veil, ever since Sirius died in her fifth year. The dark curtain rippled, with strange whispers beckoning. She didn't suppose any Muggles had discovered it since the Ministry building itself had collapsed, although it was hard to miss a kilometer-wide hole in the ground. Perhaps it was in a separate dimension.
She focused again on the task at hand, trying to gather enough grains of time-sand to refill a magical hourglass. They were shattered across the ground, mixed in with dirt and pieces of stone and tile. The main problem of Time-Turners, however, is that they only take the traveler back a few hours. She needed years and years. It was frustrating. She felt the pull towards the Veil again, and this time, she walked up the dais. Her outstretched hand did not reappear at the other side. She flexed her fingers, feeling the cool, soft sensation. She stretched her arm further in, then withdrew and inspected it. It didn't look dead. She thought of other worlds that it could lead to, parallel universes where she lived her life like she would have if everything had just turned out right.
Quantum physics said that time was divided into slices. Each frame of time was a different world, that branched off with every decision or random happenstance. Those branches would never meet again. If she would just travel along the branch, backwards, to the place where it all changed for the worse… There was the Time-Turner problem. There was the problem of where Sirius went when he fell through the Veil. She kept carefully refilling, watching the grains magically trickle in. The Veil beckoned. What if, she questioned, one combined the two? Both took you somewhere, even if it was the spiritual realm.
She stood up and twisted the tiny hourglass, now repaired. With the Time-Turner still spinning, Hermione stepped backward into the Veil with a small thrill of anticipation. What did she have to lose?