One of the more lovable characters in Angel, Allen Francis Doyle (Glenn Quinn), left the show tragically; discussions were had about bringing his character back to life, but this didn't end up happening due to real-life circumstances.
Armed with a darker premise and Joss Whedon at the helm, the 1999 spin-off series to cult TV show, Buffy the Vampire Slayer, Angel focused around David Boreanaz's character that was first introduced as Buffy's (Sarah Michelle Gellar) primary love interest. A vampire with a soul, Angel's tragic history—and eternally looming potential as a villain—made him one of the more intriguing and complex characters in the teen supernatural drama. After his departure in season 3 of Buffy the Vampire Slayer, Angel took to the streets of Los Angeles, a Batman-esque figure protecting the innocent to atone for his centuries of bloodshed.
Allen Francis Doyle—known simply as Doyle—was introduced in the series premiere, "City of Angels", as a messenger of sorts for the Powers That Be. Doyle is a demon who gets random flashes of visions; this is how Angel gets roped into helping people, primarily, and leads to him starting Angel Investigations, a private investigating firm that "helps the hopeless". With his witty one-liners, endearing crush on Cordelia (Charisma Carpenter), and insider knowledge of the demon world given his true nature as a half-Brachen demon, half-human, Doyle was an excellent addition to the team. However, his tragic departure from the show and real-life circumstances got in the way of his character being brought back.
Doyle's Return Story Explained (& Why It Didn't Happen)
Doyle only appeared on nine episodes of Angel. While certainly a short time, it was enough to make and leave a lasting impression on fans of the series and secure his place in the larger universe. Even so, Doyle managed to help Angel out of numerous difficult situations, nurture a budding friendship with Cordelia that bordered on romance, and took the traditional exit for many a Buffy character gone too soon—the sudden death heroics. Doyle sacrificed himself for the greater good, which on Angel, became par for the course; throughout the series, redemption and self-sacrifice are two of the most present themes. While still tragic, Doyle's on-screen death wasn't meaningless. There was some closure for his feelings for Cordelia that he'd been harboring since they first met when he kissed her and passed along his visions; she then stepped up to the plate as the liaison between Angel and The Powers That Be.
Despite Glenn Quinn struggling with substance addition off-screen, he was dear to his fellow cast members, so bringing him back in some capacity was discussed behind the scenes. Some deaths on shows like Buffy the Vampire Slayer, Angel, and Supernatural are certainly permanent and tragic, but given the magical universe and the blurred lines between life and death, not everyone stays dead. Tim Minear—one of the show's writers/directors—spoke about being "shot down" whenever he suggested bringing the character back. Minear and David Fury—one of the show's writers/producers—both mentioned how the intent was to possibly bring Doyle back as one of the series' "Big Bads", perhaps in season 3; Fury made this comment in an interview in Dreamwatch #118.
Doyle never seemed the type to become a Big Bad, as he was marked by a gentle nature despite his half-demon ways; he was charitable and good, genuinely benevolent and interested in helping others. Beyond that, him returning as a villain would add less weight to his heroic sacrifice. However, any opportunity to bring Doyle back to the show became impossible after Glenn Quinn tragically passed away in 2002 at the age of 32. Angel would go on to have other notable villains, and fans of the character—and actor—got the closure of Doyle's goodness showing through his choice to go out a hero rather than inevitably dying a villain, if he returned in the proposed capacity.