Knight for a Day begins with an enchanted ancient stone, half-buried in Henry's garden. This was the stone once used by the great wizard Merlin to hold a sword that only the trueborn king could draw out.
Thirty years after it brought Arthur to the throne, Merlin uses the stone's power once more. He summons Henry from the future in a risky gamble to protect the realm from the treachery of the villainous Sir Mordred.
The mysterious stone transcends time and links Henry with Camelot, primeval magic, Merlin, King Arthur, the lost scabbard of Excalibur, Camlann and a perilous quest.