The L.M.D (Life-Model Decoy) arc in Marvel's "Agents of S.H.I.E.L.D." has ended on Season 4 Episode 15 titled "Self Control." Now, a new storyline has started and it comes with many questions that need to be answered.

This new arc, which is called Agents of Hydra, will premiere on "Agents of SHIELD" Season 4 Episode 16 titled "What if..." It continues the event after Daisy "Quake" Johnson (Chloe Bennet) and Jemma Simmons (Elizabeth Henstridge) hack their way inside Holden Radcliffe's (John Hannah) Framework, Comicbook reported.

The twists that the viewers saw on "Agents of SHIELD" Season 4 Episode 15 "Self Control" were no doubt surprising - to say the very least. Alphonso "Mack" Mackenzie (Henry Simmons) is living a rather quiet life inside the Framework, presumably with her deceased daughter. And Phil Coulson (Clark Greg), on the other hand, has traded his agent life to be a normal citizen: a teacher, to be precise, according to Entertainment Weekly.

What caught many fans off guard in "Agents of SHIELD" Season 4 Episode 15 "Self Control," however, is the Framework lives of Agent May (Ming-Na Wen) and Daisy. The former is now working for the underground terrorist group Hydra while the latter has been reunited with her past love interest, Grant Ward (Brett Dalton).

Dalton, who played as Ward in "Agents of SHIELD" Seasons 1 through 3, has been confirmed to return as a guest star in Season 4 Agents of Hydra arc, show's executive producer Maurissa Tancharoen confirmed to EW. She didn't, unfortunately, reveal any specific details about what type of Ward will people see in episode 16.

Meanwhile, Jemma Simmons' life inside the Framework has also shocked the fans. When speaking to Daisy before they jump in, she told the SHIELD Inhuman that when they die inside the virtual world, they will also die in the real world. However, the Simmons inside the Framework is already dead, which raises some questions from the fans who saw "Agents of SHIELD" episode 15. But the series producer, Jed Whedon, who also made his directorial debut in "Self Control," has offered a brief explanation about the character's life inside.

"Well, they're plugging into their avatars. They say they've located the avatars and they'll just plug into them," Whedon told IGN. "It's a made up digital world, so there are certain rules that can be bent."

The third - and presumably final arc - of "Agents of SHIELD" Season 4 Agents of Hydra, will premiere after the show's one month hiatus. Episode 16 "What if..." will return on ABC on April 4, 2017.