Hermione had been able to scrape pieces together of what happened in Harry's childhood. But she had never managed to get the full story. That is, until after one too many nightmares in the tent, Hermione decided to take fate into her own hands and ask him. What she didn't expect, was that she'd find a kindred spirit in her best friend. (Canon-compliant except it's now not 1997)

Harry just wanted to help, but he ends up receiving the best repayment ever imaginable.