Just ten days later , on 29 July , the `` Book 3 : Fire â `` Volume 4 '' DVD was released , which contained the four episodes as well as episodes 56 and 57 ( episodes 16 & 17 of third season ) , audio commentary from the series ' co-creators , cast , and crew , and a comic book . Just ten days later , on July 29 , the `` Book 3 : Fire â `` Volume 4 '' DVD was released , which contained the four episodes as well as episodes 56 and 57 , audio commentary from the series ' co-creators , cast , and crew , and a comic book .