Rebels High S01 E03 New problematic teacher?

Pasha's younger brother finds a combat grenade. Pasha brings a grenade to school, and Lola wants to film it. Jean wants to win the attention of his classmates, which is why he trains freestyle. The headteacher of the school is digging under the new teacher, she wants to understand why she closed her business and went to work at the school as a teacher.