When does Angel return?

The series was created by Buffy's creator, writer and director Joss Whedon, in collaboration with David Greenwalt. It aired on The WB from October 5, 1999, to May 19, 2004, consisting of five seasons and 110 episodes. The show details the ongoing trials of Angel, a vampire whose human soul was restored to him by a Romani curse.
The series focuses on Angel (David Boreanaz), an Irish vampire who is over 240 years old. Angel was known as Angelus during his rampages across Europe, but was cursed with a soul. He left Buffy the Vampire Slayer at the end of season 3 to move to Los Angeles in search of redemption.