Help - Hammerlorne levers

[istara]

I'm in an area with three levers around a square pit in the south of the screen.

Two of the levers are behind fences. Sometimes I can slip through the fences. Sometimes they're solid. Sometimes they're open.

But I can't spot a pattern and nothing seems to open - or make slippable-through - the presumable exit gate to the southeast.

Thanks in advance for any help!

[Kreador Freeaxe]

You flip the switch in the open, that opens one of the switches behind a gate, which opens another switch behind a gate, which opens the final switch behind a gate near where you entered the area, which opens all the gates.