“What’s a patronus?” Zhenya asked Dimitri. He was in his last year and was practicing the patronus charm.
“It’s just an object you can conjure from your wand that acts as a protection against Dementors. You remember those don’t you?” he asked.
She nodded slowly. They terrified her.
“Expecto Patronum,” he said loudly and confidently. Out from his wand burst a Lion! It stood there, looking around; probably for a Dementor.
When it spotted Zhenya, it walked over to her and stood a small distance away from her.

She was frightened.
“Pat it,” Dimitri said.
She held out her hand.