Ruby Roundhouse

Martha lands in detention with Spencer, Fridge and Bethany and becomes Ruby in the game. Her strengths are karate, tai chi and aikido, and her weakness is venom.

The girl who barely spoke at school finds her new body knows how to fight on its own. She got detention for talking back to her gym teacher, and she was the girl who avoided every sport.

To distract two guards, Martha has to flirt, and her teacher is Bethany, in Professor Oberon's body. It goes badly until she switches to fighting to the beat of the music, in one of the movie's best-remembered scenes.

Along the way, Martha and Spencer grow close, and she helps get the Jaguar's Eye to the statue. Ruby becomes the group's muscle in a fight, while Martha learns to trust herself outside the classroom.

When Spencer vanishes into the repaired game, Martha decides to go after him. She's the only one who lands in the same avatar as before.

With Eddie and Milo lost in Bravestone's and Mouse's bodies, Ruby becomes the one who knows the rules and leads the group. She has to explain to the two of them that they're inside a video game, which takes them a while to accept, and that each player's three lives show up as stripes on the forearm. Losing the last one means dying for real.

Ruby fights alongside the group against Jurgen the Brutal, and the mission ends with the Falcon Jewel back. Outside the game, Martha and Spencer patch things up.

Back home, Martha sees a more confident Spencer, and the two leave their college rough patch behind. Martha comes back knowing Ruby's nerve was hers all along. The group that met in detention comes out of the second game closer than ever.

Karen Gillan plays Ruby in both movies, and Morgan Turner is Martha outside the game.