See if this helps, till some wiser sage logs on to respond...
do as it says, walk (or judiciously run) thru the central fire, then back, then around the edges, *BUT* heal your party often between the fires! There's no time constraint here, so long as you don't step through the central fire again before hitting all the peripheral fires. So slow down and think and heal... When you get to the gate, it should be open.
I *think* that's the answer! I always take the warrior's path myself
