If the spike is brown/dead it cannot be getting anything from the roots of the mother plant. I'd cut it off immediately and plant it into a small 1 3/4" pot with a media that retains moisture really well - like coir or sphag. I'd mist it a little around the base area each morning to keep a little moisture in the area to encourage some additional roots to sprout and start the waiting game. It is going to be a LONG process - but can be rewarding in the end. Post us a pic when you get it done so we can admire your efforts!
