The Ghost - S2.E35

A convocation of the world's greatest scholars is being held in Camelot under Merlin's direction. The wizard's pleasure at the wonderful turnout turns to fear when he spots a face from a past event he has long kept hidden from Arthur. His terror at being exposed causes him to shun virtually everyone at the celebration, including his old friend The Mighty Oom. But a series of mysterious accidents may force Merlin to confess his greatest shame to preserve the safey of those he loves.