One Knight Only
by Peter David

Description:
Arthur Pendragon, the Once and Future King, has pursued his political career all the way to the White House. Then tragedy strikes, in the form of an assassination attempt that leaves his wife Gwen at death's door. To save her, Arthur must once again seek the Holy Grail, the Cup whose magical powers can heal her body and soul...

And as Arthur knows from experience, grail-hunting can be a very dangerous occupation.