Even if she could find the words, Katie really just couldn't speak anymore. She was all choked up with fear and angry and sadness, tears still streaming down her cheeks. T took a step back and part of her was grateful because she didn't know what to make of him anymore, didn't know if she was supposed to be afraid. But at the same time, in that last second before he Apparated away, there was a part of her that wanted to shout for him to stop. Not because she trusted him at all right now, but because he was the only one she knew who might understand everything in her head... especially since he'd helped to put it there. And no matter what had just happened, a part of her still thought of him as a friend.
But she didn't open her mouth, or maybe couldn't, and T disappeared with a pop, leaving her standing in the middle of the empty park with Quaffle by her side. All the energy went out of her with him leaving and she collapsed on the ground in a tangle of limbs, tears streaming down her cheeks as she sobbed. She should go home, she knew that... but for the moment it was all she could do to huddle there, feeling completely lost and overwhelmed... and very, very alone.