What happens when Richard calls forth the ancient spirits?

Richard calls forth the ancient spirits, including that of Darken Rahl. Darken Rahl explains that since Richard is his son, only Richard could have called him back from the dead to loose the Keeper from the underworld. Darken touches Richard and leaves Richard with a mark. Kahlan can do nothing for Richard, but a spirit follows Darken Rahl and saves Richard. It is the spirit of Denna, who tells Kahlan that Kahlan must do whatever it takes to save Richard and stop the Keeper.