Call 999 as you arrive. Say exactly this:
"I am at [Pickup Location] extracting a 26-year-old victim of incest and severe domestic slavery. Her uncle has sexually abused her almost daily for a decade. He raped her at 14—he is on the birth certificate as the father. She has zero freedom: no phone, not allowed out alone, total control. The aunt poses as the boy's mother. Because she is escaping, the uncle and aunt have a strong motive to make the 11-year-old boy disappear to keep their control over the property. Her life is in immediate danger. I do not know the boy's name or school yet, but I will get it the second she is in the car. I need the CSE Major Investigation Team standing by to secure the boy IMMEDIATELY."