'Agents of SHIELD' Finally Reveals What Happened to SPOILER

Tonight's episode of Marvel's Agents of SHIELD, "Inside Voices," finally revealed the fate of a character who basically vanished from the show towards the end of the end of the show's first season.

SPOILERS for Marvel's Agents of SHIELD, "Inside Voices," follow.

The main plot of "Inside Voices" involves Carl "Crusher" Creel, aka the Absorbing Man trying to absorb the properties of gravitonium. The gravitonium reacts violently to this attempt and Creel ends up with two competing voices in his head trying to instruct him on what to do.

One of the voices is clearly Dr. Franklin Hall. Hall is the former SHIELD scientist who specialized in dealing with gravitonium. When gravitonium fell into the hands of industrialist Ian Quinn, who wanted to weaponize the gravitonium, Hall allowed himself to be taken hostage by Quinn so that he sabotage Quinn's plans from the inside. SHIELD, oblivious to Hall's plans, sent in Coulson's team to rescue Hall, but Hall fell into the gravitonium during a fight between Coulson's team and Quinn's forces.

In the Marvel Comics universe, Hall becomes the supervillain Graviton. So far that hasn't happened, but Hall is apparently alive within the graviton and giving it sentience.

So then who is the other voice within the gravitonium? During the Hydra uprising, John Garrett became increasingly unstable after injecting himself with the GH 325 serum. Quinn and Raina, who had been aligned with Hydra and Garrett, decided to abandon their former allies and take the gravitonium with them. Raina returned to help lead Daisy Johnson to her father and her Inhuman origin. Quinn was never heard from again.

The tag to "Inside Voices" finally ties up that loose plot thread. Oscar-nominated actress Ruth Negga returns as Raina in a flashback scene, along with David Conrad as Quinn. The scene takes place just after the two of them have left Garrett behind. They're in a transport vehicle with the gravitonium. Quinn expresses his gratitude toward Raina for helping to get him away from Garrett and for giving him the Gravitonium.

However, Raina has to break the truth to Quinn. She isn't actually giving the gravitonium to Quinn. It turns out that at this point Hall is already sentient in the gravitonium and he wants payback on Quinn. Raina gives Quinn to the gravitonium, which consumes Quinn, presumably making him the second voice inside Creel's head.

Are you happy to finally know what happened to Ian Quinn? Let us know your thoughts in the comments!

Marvel's Agents of SHIELD airs Fridays at 9 pm ET on ABC.