The king's witch

the long version

"During the Third Crusade, deaths from fever and starvation are common, but King Richard the Lionheart has a secret ally against these impassable enemies--a mysterious healer by the name of Edythe. Of all the women in Richard's life, she is the least known...and perhaps the most powerful. Sent to Richard by his mother, Eleanor, Edythe is first thought to be a spy. She does have her fair share of secrets...owing not only her station in Richard's camp, but her very life, to the enigmatic Queen Mother. But when Edythe's medical knowledge saves Richard from a grave illness, she becomes an indispensable member of his camp--even as his loyal soldiers, suspicious of her talent for warding off death, call her witch.."--