So, when you want to go meet with Sebastian in Chapter 1, you apparently call him on the phone, only for him to hang up and come through your door within seconds.

So... how exactly did we call him? Isn't he right outside our apartment I thought?

"Hey, Sebastian. This is (Your Name Here)."

(Huh, he just hung up.)

Do cell phones exist? Part of me doubts there's a payphone outside, and even then, he is outside guarding our door. Why not just open the door and call Sebastian inside?