Follow and capture the challenger

You took a moment to glance at Wally moving over to talk to your father, then went back out the door. At first you didn't see her, but then you heard sniffling from around the corner of the gym, followed by a cry of anger and a dull thud.

You poked your head around the corner, and saw the girl who had challenged your father glaring at the wall of the gym, her fist still against it where she had punched it and tears in the corners of her eyes.

You quickly glanced around, and seeing no one watching, you took your chance before the trainer noticed you and threw a pokeball at her. She noticed the motion and jerked her head to look at you, one arm going up to try and block the ball heading towards her face. But the pokeball just activated when it hit her arm instead, and she disappeared in a flash.

The ball shook once...

Then clicked.

You blinked in surprise, then walked to the ball and picked it up. Wow. Her emotional state must have really lowered her defenses against the pokeball for that to happen.