turn off the lights and look for writings in the box with the flashlight.
Again: Steve is absolutely sure that flashlight isn't for revealing secret messages, because its lamp and its light isn't special.
Besides, he feels he will have to use it again, and he don't want to stay in situation, when he is in absolute dark and suddenly flashlight's energy ends...
Remember this mechanism that was opening and closing cache in the upper room? Open it, put box inside, so that it blocking the cover and close.
Wow, suddenly good idea! Steve runs in upper room's cache...
Wait. But... this mechanism closes cache's hole where lock located! Even if he puts metal box inside cache, it will not be opened with this way...
Damn! if this mechanism
shut down the whole cache, then, Steve believes, its power would smash box's side, and it would be opened...
But it doesn't.