Iridis' recalled an esoteric text he'd once read describing variant spells on the Wall of Fire that talked specifically about a Wall of Light, able to be cast only by those who were pure of heart (though it was always hard to tell if that was true or if the author had taken some liberties). His memory, almost perfect when it came to spells, recalled that the wall would only harm the undead or infernal beings.<br/><br/>If this a Wall of Light, such as he was familiar with, it must be finite in length and would presumably end on its, unless a spellcaster was actively sustaining the spell or had an object that kept the wall in place. There was also a small gap between the wall and ceiling, where a particular dexterous individual might be able to get over the top of it, though the stairwell was cramped enough that it would take an impressive feat of athleticism, with little room for run up.