Agents Of SHIELD: 10 MIA Characters Who Should Return

2. Ian Quinn

Last Seen: Parting ways with HYDRA - with Gravitonium in hand - in "Beginning of the End," Season One's finale. Considering how big a part Quinn played in the show's debut season, it's surprising we haven't seen or heard from (or about) him since. He shot and left Skye to die, took part in Mike Peterson's mutilation, and caused a host of other problems for the team along the way, but managed to escape the season scot-free. In essence, Quinn is a huge loose-end the show has yet to tie up. Hopefully, those behind haven't just moved on from the character, with the silence around him meaning he'll be back with a vengeance down the line, which would pack a lot more power if the series also brings back our final character on this list.