who's stiles?

A man in a dark hat and coat stands in a dimly lit hallway, his hand moving to his face as he looks down, then the scene cuts to a close-up of his face showing a serious expression, followed by him walking down a school hallway with lockers, touching one as he passes, then a hand uses a red marker to highlight text on a paper, then a hand holds a photograph of three people, and finally a close-up of a list of names written in black ink on a light blue surface.