Season 2 Episode 12
First Aired: June 25, 2010
Description: When the Fires of Idirsholas burn for the first time in 300 years, Gaius fears it heralds the return of the Knights of Medhir. When Arthur and Merlin return to Camelot, they find out that eveyone except for Morgana is under a strange enchanment. As Morgause and the Knights attack a helpless kingdom, Merlin finds his loyalties stretched to the limit.