The fourth season of “Agents of SHIELD” won’t come until fall. But Marvel has already begun teasing what the show’s next installment has in store for fans.

According to ComingSoon.net, a trolley in San Diego was recently spotted decked with “one Hell of a teaser image.” The train had the image of a flaming chain across its body, plus the words: “Get fired up! Marvel’s ‎Agents of S.H.I.E.L.D.‬ knows how to get you to ‪SDCC‬ in style.”

This teaser lead some fans to believe that Ghost Rider might just drop by next season. This is totally plausible now since Marvel has already gotten the rights to this character back. However, as the film blog pointed out, the flaming chain doesn’t really confirm a cameo from Johnny Blaze, since a S.H.I.E.L.D. character from last season, Hellfire, also uses this as a weapon.

Meanwhile, Elizabeth Henstridge, who plays Jemma Simmons on the show, teased what she knows would happen to S.H.I.E.L.D. next season. “I’m really excited about where we are going… we have a later slot, which might open the door to discuss some darker issues,” the actress told Huffington Post. “Our show seems to have gotten progressively darker each season, which allows the writers freedom to explore [more] things.”

But when pressed for details, Henstridge decided to keep mum. “I honestly don’t know anything about season four!” she said. “I haven’t seen or read anything yet!”

The actress, however, did admit she is looking forward to the next season. “I just can’t wait to get back to work,” she explained. “This makes me want to get back to work more than ever – seeing the devotion of these fans that show up to… express their love and excitement. That makes me just as excited!”

A release date for “Agents of SHIELD” Season 4 has yet to be confirmed.