I am back in the first corridor because I need to activate the switch, I think this is the right one, before I can go up through the gates into Daryl's office.
How do I activate it? Each time I swipe at it, there is a strike of light but nothing appears to come on. As you might gather, I am spent several hours here already and just want to finish this. I haven't opened the chest, if that's any use. Any help would be appreciated. Thanks.