"Episode 4.06 – The Good Samaritan The shocking origin story of Robbie's transition into Ghost Rider is revealed as the lives of Coulson and the team hang in the balance."

There's a couple ways this could go, and all of them are pretty badass. Here's a quick breakdown of some possible origin stories, drawn from the comics and beyond:

Robbie Got His Powers From the Devil

In the original Ghost Rider comics with Johnny Blaze, Johnny summons up a demon called Mephisto to cure his father's cancer, selling his soul in the process. Unfortunately, both Johnny and his father (incidentally named Crash) were both daredevil stunt motorcyclists, and Crash died attempting a stunt in their travelling show soon after his cancer was cured. From there, Mephisto bonded Johnny with a demon called Zarathos (a Spirit of Vengeance) and forced him to become the Ghost Rider. This is the Rider most people recognize: the one with a leather jacket, chain, and chopper motorcycle.Robbie doesn't have the whole stunt-motorcycle backstory, but he might have also summoned Mephisto to save a loved one. We don't know too much about Reyes right now, but some personal tragedy may have prompted him to sell that juicy soul of his.

Robbie Got His Powers From Eli Morrow

In the current Marvel comics series Robbie Reyes' iteration of the Ghost Rider actually got his powers from another source: a ghost named Eli Morrow. After being murdered at the hands of mercenaries while trying to participate in a street race, Robbie is brought back to life by a spirit bound to the now-iconic muscle car, which turns out to be a serial killer named Eli Morrow, who is actually Robbie's estranged uncle. Eli was a Satanic ritual murderer, and it takes the intercession of the real Ghost Rider to get him under control. Eventually, Robbie bonds his spirit with Eli's, making a deal to sate his uncle's bloodthirst by only killing evil people.This one makes a lot of sense for the TV version of Robbie, since it was his story to begin with: it shows his complicated nature and explains his riding the line between good and evil. At the same time, it removes Robbie from Ghost Rider's original association with Hell and demons, which can be a lot of metaphysical baggage for the show writers to carry around. Ghosts are easy by comparison.

Robbie Got His Powers From the Darkhold

Earlier in the season we saw that a scientific research facility in LA had been overrun by ghosts, which were actually scientists who had been transformed by the power of a magical book called the Darkhold. Robbie had a hand in cleaning up the mess, but the actual Darkhold was never seen. For fans of Doctor Strange, though, the book is a familiar fixture: it's one of the books Doctor Strange uses in his magic, but mostly he keeps it away from people who might use it for evil. Which makes sense, because the Darkhold is essentially the ultimate book of dark magic and can corrupt anyone who reads it or tries to use its spells. It's essentially Marvel's version of the Necronomicon (and shares some resemblances to it in the lore).This theory has weight because the Darkhold has actually been referenced in the show, along with its magical powers. The original Johnny Blaze was able to summon Mephisto by using some unnamed occult book, and guess what, that's what the Darkhold is (at least canonically). When you've got a ghost-shaped hole in a show (in the case, Robbie's origin), its origin may have something to do with the only ghost-shaped peg available.No matter where he got his powers, Robbie is still a very interesting addition to the show and a super-cool character to add to the mix. Magic is always hard to pull off in shows like this (just ask Arrow about that), but hopefully AoS will do it right.The next episode of Agents of S.H.I.E.L.D will air October 18th at 10/9 central on ABC.