the offices in/on/along the hall

[Topstudent]

I'm trying to write a script. The scene is taking place in a hall/hallway/corridor on the ninth floor in an office building. Two police officers are searching the offices in/on/along the hall.

Question: Is 'in', 'on', or 'along' correct/natural here?

 

[emsr2d2]

You need "on the ninth floor of an office building".
I'd say "searching all the offices along the corridor".