If the cephs around share the same conditions and still look fine, you should also consider a fungus attack. These little bastards can kill your plants within a few days, and the pics you showed look pretty much the same to me. Maybe the plant has been weakened by some inappropriate heat before.
I'd remove all the withered leaves and pitchers, repot the rhizom into fresh soil (and a new pot!) and treat both this ceph and all of the cephs around with a fungicide. There is no guarantee for a recover, but I'd give it at least a try. With a little luck, the ceph will grow out of the rhizom again in a few weeks or months...
Good luck and successful growing!