The left hall-that seems darker then usually

You precede to the left hallway, keeping your guard as you do. As you do, you notice the number of torches that have been giving you light so far, seem to be littling as you walk, So much so, you had the take the last torch you in the hall to continue on.

After a good few seconds of walking later, you find that hallways design changed. The walls, seem to have holes in them, and the floor patterns had some engravings now. Your not sure what to think of it, but it does catch your eye.

You take another step, and the stone plate underneath your foot presses downwards, oh uh! IT'S A TRAP! You quickly flitch, and brace yourself for whatever might happen to you. After few seconds, nothing, nothing happens to you.

You jump backwards, off the stone plate and you watch it regain the look of a normal plate. Maybe, it was dud, or a maybe it was suppose not to do anything. Either, you count your blessings, since nothing happen to you. Still, your not internally sure what to do now. Do you look around, to see how you're suppose to get threw, or around it? Or do you head back?