Here's Looking At You is the 23rd episode of Sabrina's Secret Life.
After promising Maritza she would help her with her class volcano, Sabrina gets late for Witch School, where she gets introduced to a guest speaker in a magic mirror, that favourites Sabrina because she is a half-witch. Meanwhile, Maritza fails her volcano after the vinegar splatters in her face. On her way out from the class, the remains of the top of the volcano spill on Cassandra's shirt, who happened to be walking with Sabrina when she bumped into the volcano. Sabrina runs after Maritza, who cancels their friendship, when she reminds Sabrina that she forgot to help her. Later on in the day, when Sabrina and Cassandra return to Witch School, Cassandra falls in through a portal in the magic mirror, after Sabrina cast a spell on her for insulting her in front of the mirror. Sabrina gets pulled into the portal with Cassandra, where they reappear in a modified version of their class. Mr. Snipe is the principal, and he introduces them to a mortal guest speaker who will lecture them on the world of magic. That's when Cassandra realizes that she is mortal (proved when her spell completely fails). When they exit the classroom, everybody (except for themselves), are witches. Maritza takes Cassandra's position: being the best witch in the school, and hanging around with Tiffany and Margaux. They make fun of Cassandra, and turn her into an inflatable balloon. Sabrina becomes Maritza's friend again, after they join their broken-heart pendants together. They then go to find Cassandra who got turned into a frog by Tiffany and Margaux after she asked for their help. Once Maritza turns Cassandra back, they go through the magic mirror into the real world; where Sabrina reconciles their friendship.