The Salome Arc is a story arc in Shinyaku Toaru Majutsu no Index, covered in Shinyaku Toaru Majutsu no Index Volume 15.[1]
The day after the High Priest's rampage and his encounter with World Rejecter, Kamijou Touma and his classmates are forced to attend another school for lessons due to the damage to their own school. Once there, Touma finds that Kamisato Kakeru is also attending as a transfer student. At the same time, the latter's adoptive little sister, the Mass Murderer Salome, arrives in Academy City, with her eye on the Kamijou Faction.[2]