The final arc of Agents of S.H.I.E.L.D.'s fourth season has seen the introduction of The Framework, a digital alternate universe created by Dr. Holden Radcliffe and his increasingly troublesome Life Model Decoy assistant, AIDA. Radcliffe's creation is designed to be exactly like the real world but with the one biggest regret of the people plugged into it removed and predictably, life has played out very differently.

Aside from HYDRA gaining power and S.H.I.E.L.D. being forced into working as an underground resistance movement, the Framework arc has allowed a variety of characters from the show's past - either deceased or departed - to make their return. Most notably, Agent Grant Ward has reappeared (again) as a bona fide protagonist, fan favorite Agent Triplett is back with the team and HYDRA operative Sunil Bakshi has also rejoined the cast.

Conspicuous by their absence so far are everyone's favorite dysfunctional superhero couple Bobbi Morse - a.k.a. Mockingbird - and lovable Brit, Lance Hunter. The duo were popular additions to Agents of S.H.I.E.L.D. season two, with Morse providing a strong, ass-kicking female agent to rival Melinda May and Hunter bringing a healthy dose of humor and heart to the table. Such was the characters' popularity that they were earmarked for their own spin off series titled Marvel's Most Wanted and so were written out of A.O.S. in the episode 'Parting Shot', which saw the couple forced into severing all ties with S.H.I.E.L.D.

Unfortunately, Most Wanted never progressed any further than a pilot episode and this left Mockingbird and Hunter without a home in the Marvel Cinematic Universe. Speaking on their potential return, executive producer Jeffrey Bell claimed that inserting Bobbi and Hunter straight back into the S.H.I.E.L.D. fold would undermine the emotional events in 'Parting Shot', and although the door was open for them to come back, it would have to be under the right conditions.

Seemingly, The Framework provides a golden opportunity for Bell and co. to re-introduce Lance Hunter and Bobbi Morse without ruining the emotional impact of their exit. It also averts the need for the tedious explanations of where they couple have been and how they can rejoin S.H.I.E.L.D. that would inevitably occur if they made a comeback in the real world.

Interestingly, Hunter's return has already been hinted at by the actor behind the character, Nick Blood when he posted a behind the scenes shot of himself with actor Henry Simmons, who plays Mack. Although he could simply have been catching up with an old pal, earlier social media posts by B.J. Britt (Trip) that showed himself and Simon Kassianides (Bakshi) mingling with the Agents of S.H.I.E.L.D. cast sparked rumors of their return and later proved to be right on the money. Furthermore, neither Blood or Mockingbird actress Adrianne Palicki are currently working on any sizeable projects that would leave them unable to do a couple of weeks shooting for S.H.I.E.L.D., and so practically speaking, a comeback is certainly viable.

But what about from a narrative perspective? How do the characters of Bobbi Morse and Lance Hunter fit into the reality generated within The Framework?

The digital world has thus far proven to be highly unpredictable with regards to whereabouts and personalities of its characters. For instance, who could've ever seen Fitz as a ruthless villain? But the fate of S.H.I.E.L.D. as an organization in The Framework provides some potential clues as to the fate of Bobbi and Hunter and could even indicate that only one of the duo will actually be making a reappearance.

When Agents of S.H.I.E.L.D. first introduced Mockingbird, she was a highly decorated and loyal agent, trusted completely by Nick Fury when the HYDRA attack of The Winter Soldier kicked off and, as such, it's probably reasonable to assume that Bobbi would also be a S.H.I.E.L.D. agent in The Framework. Sadly, this reality's version of S.H.I.E.L.D. was said to have been mostly wiped out as a result of the Cambridge Incident.

Essentially, The Framework removed Agent May's regret of killing an Inhuman child in Bahrain. Said child subsequently goes on a deadly rampage. This allowed HYDRA to capitalize upon a fear of Inhumans and seize control and, in the process, massacre S.H.I.E.L.D. Because of this, S.H.I.E.L.D. operatives in The Framework appear to either be working with Jeffrey Mace's resistance movement or deceased and although it's entirely plausible that Bobbi made a miraculous escape and is currently in hiding, her absence in the resistance group means it's more likely that she was caught up in the fray and killed.

Happily, the prospect of survival looks far healthier for Lance himself. In the primary Agents of S.H.I.E.L.D. timeline, Hunter's early relationship with S.H.I.E.L.D. is highly informal, with the character working for Isabelle Hartley and largely considering himself a "freelancer" until later becoming loyal to Coulson. Consequently, there's a high chance that Hunter was nowhere to be found when HYDRA murdered most of S.H.I.E.L.D.'s operatives and that he's currently safe and sound elsewhere.

However, if this is true and Hunter is being his typically lone-wolf self in The Framework, what possible motivation could he have for returning in the near future?

This largely hinges of whether Lance and Bobbi are romantically involved in the digital universe. If they are - and there's certainly no reason why they wouldn't be, seeing as they were always drawn back to each other in the real world - then Hunter could currently be out for revenge against HYDRA. Assuming that Bobbi was killed alongside many others in the destruction of S.H.I.E.L.D., Hunter is certain to be seeking payback and is unlikely to have sought out the resistance for help due to his nature. This not only explains his absence in The Framework so far but also gives him a ready-made reason to join the fight.

While Daisy, Coulson and co. are fighting HYDRA, attempting to escape The Framework and also prevent the completion of Project Looking Glass, Lance Hunter may simultaneously be on a one-man mission to bring down the group himself and if they all happen to cross paths, cooperation will surely be on the cards. This would also explain why Nick Blood has hinted towards a return on his social media but Adrianne Palicki has not.

Inevitably, of course, the time will come for the core cast to exit - and most likely destroy - The Framework and therefore Hunter's (and possibly Bobbi's if she's alive) return to Agents of S.H.I.E.L.D. is sure to be a brief one. There has been speculation that Project Looking Glass' ability to create real people using the Darkhold's power could mean a permanent return for either Agent Triplett or Grant Ward. However, seeing as neither Hunter or Bobbi are dead in the real world, it seems unlikely that the machine will be used on them.

Another possibility does remain, however - that neither Bobbi or Hunter will appear in The Framework, and instead the genuine versions of the characters will be re-introduced in season five. It would be strange indeed if the Framework story passed by without a reappearance by at least one of the popular duo and the only explanation would be that they're lined up to rejoin the permanent cast in the near future. After all, the duo only exited to film a doomed spin off and enough time has passed since their exit to justify a comeback.

And it isn't only Lance and Bobbi who could feature in the upcoming Framework finale. MCU veteran and HYDRA operative Agent Sitwell is sure to be alive and well given how his group are thriving. He's likely to be a high-ranking member of the organization and could be drafted in by Fitz to quell the rebellion. Other figures such as Maria Hill and Crossbones are also sure to be present somewhere but are unlikely to appear in Agents of S.H.I.E.L.D. due to their commitments in the movies.

However things ultimately play out and whichever characters reappear or not, the Framework arc has certainly been a high point for the series and has provided plenty of thrills whilst also feeling very fresh thanks to its alternate reality premise. The return of Bobbi and Hunter would just be the icing on the cake.

Agents of S.H.I.E.L.D. continues with 'Farewell, Cruel World!', May 2nd on ABC.