hey ! I'm quite new here, but i think i can help.
the secret area:before you leave MIPO4CO5 get on the large ledge on the left of the vertical saw.run jump right over the saw
you should land on a little ledge.hoist yourself up.you should then be on MIPO4C10.
up above you should see that ring.pull it .
If you missed the secret before, walkover and frre them i think.drop back down to C05 and carry on!
I hope that helps jericho rulz 2k