The cord

It's a multilayered cord channeling an invisible matter; it grows outside in and few things are as resilient as its core. No matter what harm is done to its outter layers, the deeper it penetrates, the harder it gets to affect the protected flow. And if you let that innermost strong, still extraordinarily thin wire come into existence, then you can be certain that you'll be connected for life.

But can the superficial layers, once severely damaged, regenerate?