Princess Principal/Recap/S1/E11 Case 23 Humble Double

Quoting from Wikipedia: "Ange and Dorothy reluctantly accept General's mission and return to the school. Dorothy lets Ange go on ahead since she cannot accept having to kill Princess. Ange approaches Princess' room and finds out that Control has assigned a new team to act as her bodyguards, led by a new agent named Zelda. Ange realizes that Control no longer trusts her, as Dorothy and Chise are reassigned and replaced with new agents. Ange secretly meets with Seven, who warns her that the military has seized control of operation and put its own plan in motion. Zelda then instructs Ange to carry out the assassination on Princess in order to prove her loyalty. Ange leads Princess to a nearby airport, where she causes a distraction and both of them switch appearances to confuse Zelda's agents and escape. Ange leads Princess to a departing airship and tells her that they will be running away to Casablanca. Princess however refuses to leave since she is still dedicated to her dream to become Queen and reform the Kingdom. She locks Ange in the airship's cargo hold and returns to Zelda, posing as Ange. Zelda explains to the disguised Princess that they will use her as a symbol to rally rebellious soldiers in the Royal Army and stage a coup to kill the current Queen and replace her with the fake Princess."