Agents Of SHIELD: 10 MIA Characters Who Should Return

6. Sam & Billy Koenig

Last Seen: Billy went away to "recharge his batteries" and Sam was sent by Coulson to enact the Theta Protocol in "What They Become," the second season's midseason finale. This two-for-one deal - or three-for-one, if you count their late brother Eric - has always proved hilarious in their appearances throughout the show. Patton Oswalt nails the roles, and their absence has been quite notable, as we haven't seen either character now since this time last year. Though Triplett is no longer around to posit whether the Koenigs are more than what they seem, it'd still be fun to see them interact with characters like Bobbi, Mack, or Hunter, as well as play a role in once and for all bringing Ward down, considering he murdered their brother. Not to mention, a lot of agents haven't been wearing their lanyards lately, and someone needs to be there to keep everyone in line.