The plot of "The Quest for Saint Camber" covers a period of approximately three months, from early March to mid-June 1125. The novel begins as Prince Conall Haldane, cousin of King Kelson Haldane, meets with the Deryni adept Tiercel de Claron, a member of the Camberian Council who has been secretly working with Conall to develop the prince's Haldane potential. Meanwhile, Bishop Duncan McLain faces an ecclesiastical tribunal to confirm the legitimacy of the marriage vows he took years before becoming a priest. With the assistance of both Kelson and Duke Alaric Morgan, Duncan convinces Archbishop Thomas Cardiel that his brief marriage was legal, thus confirming the trueborn status of his son, Earl Dhugal MacArdry.