Episode 12: Day of Wrath
In which Jace is suicidal, the Clave continue to be a despicable organisation, Izzy discovers Yin Fen, Magnus' back story is further explored, Alec & Clary are forced to work together - which is always delightful - and difficult choices have to be made by all of our core cast.
This episode is jam packed with character development, poignant revelations, beautiful cinematography & directing and stellar acting all around.