"Who the hell is Flint?" was the question on the lips of Agent Melinda May at the conclusion of last week's Marvel's Agents of S.H.I.E.L.D. Though fans have gotten to know the resourceful Inhuman portrayed by Coy Stewart over the past several episodes, May herself hasn't had the pleasure. May had been separated from her fellow Agents as she found her way to the Zephyr crashed on the ruins of the destroyed Earth before them. This week's episode "Best Laid Plans" made it plain that not only is Flint an important new player in season 5, he may, in fact, be the key to getting the Agents home to 2018.

May learning who Flint is was the final prophecy of Robin Hinton, the Inhuman seer who lived through Earth's destruction and the subsequent decades of mankind's survivors living under Kree occupation. Agents Coulson, Mack, and Yo-Yo met Flint on the Lighthouse through Tess, their ally, and together they watched Flint undergo Terrigenesis and discover his Inhuman power: geokinesis, or rather, the ability to move and control rocks with his mind. Mack and Yo-Yo stayed behind with Flint to help lead the humans in a revolution against Kasius and their Kree oppressors while Coulson, Daisy Johnson, FitzSimmons, and Deke fled to the surface and reunited with May on board the Zephyr.

Related: Agents of S.H.I.E.L.D.'s Season 5 Timeline Explained

Our heroes made a number of discoveries on board the Zephyr so that the pieces are now falling into place as to how S.H.I.E.L.D. will be able to leave the future they're trapped in and travel back to the present day:

The Zephyr contains a device called an isochronous cyclotron with resonant superconducting coils. This was designed by Fitz but built by Deke's parents. The cyclotron is able to control a Kree Monolith, which was the means by which the Agents were brought to the future by Enoch and the True Believers. Naturally, since they came forward via Monolith, it's logical to assume they can also be sent back via the same Monolith. Complicating matters is the fact that Monolith has been broken into pieces and most of it is missing; through Deke, the Agents only possess a shard of the Monolith.

But if they can find the rest of the Monolith, either in the Lighthouse or somewhere on what's left of the planet, it just so happens they have a new Inhuman friend who has the power to push rocks together and reassemble the unique crystalline structure of that very Monolith: our man Flint.

However, some questions surround Flint and it's likely there's more to him than meets the eye. From what we've seen of Flint so far, he seems like a good-hearted person, but he has killed when he has to (though the same can be said for all of S.H.I.E.L.D.) Still, it could be that an Inhuman with precisely the exact ability the Agents of S.H.I.E.L.D. need to reassemble an ancient space rock that can send them back to the present seems just a tad too convenient.

Related: Agents of S.H.I.E.L.D. Finally Explains Its Time Travel

It's possible Flint, an orphan, may have some type of connection to Mack and Yo-Yo, who have taken a shine to him and even stayed behind to help him fight the Kree. Or it may be that Flint's powers could inevitably prove to be the cause of Earth being destroyed, a tragedy that Quake has been resentfully shouldering all of the blame for, along with the moniker 'the Destroyer of Worlds', since S.H.I.E.L.D. arrived in 2091.

We've already seen how the timeline plays out once (most of) the Agents return to 2018, and so far, Flint isn't among those who go back to the past. Flint seems to definitely be the vital piece of the puzzle that gets S.H.I.E.L.D. back to our time via the Kree Monolith but it remains to be seen whether Flint's impact on season 5 ends there, for better or for worse.

NEXT: How Flint Can Help Save The Earth

Marvel's Agents of S.H.I.E.L.D. airs Fridays @ 9 pm on ABC.