"Agents of S.H.I.E.L.D." tends to keep a lot of secrets, and the Marvel TV panel was no exception at San Diego Comic-Con on Friday.

Moderator Jeph Loeb shared a short video clip that peaked into the "S.H.I.E.L.D." writers' room with executive producers Jed Whedon and Maurissa Tancharoen, who were hard at work, brainstorming ideas for season three.

The husband and wife team revealed Chloe Bennet's character Skye/Daisy will be known as Quake, obviously due to her special power to start earthquakes. The team will get a new plane called the Zephyr One (bye-bye Bus) and they confirmed the Secret Warriors team, headed up by Daisy and Director Coulson (Clark Gregg).

Earlier Loeb introduced new series regular Luke Mitchell, who joined the ABC show late last season as Inhuman Lincoln. He and the rest of the team will welcome Lash, also from the "Inhuman" comics, this upcoming season.

The behind-the-scenes clip took a dark turn when actress Elizabeth Henstridge noticed the words, "Already very dead," written next to her character Simmons on the white board. Simmons was swallowed whole by a liquefied version of the Kree stone just after agreeing to a date with her best friend, Fitz (Iain De Caestecker).

(Note: Henstridge is signed on as a series regular for season three, so she won't be gone for long.)

A familiar face also popped in at the end of the video. B.J. Britt, who played the deceased Antoine Tripplett, plopped down on the couch just as the producers asked, "Who should we bring back?"

So Simmons may be dead, and Tripp could come back from the dead?

Check back with HNGN for more "Agents of S.H.I.E.L.D." spoilers before the show returns on Tuesday, Sept. 29 at 9 p.m. on ABC.