'Agents of S.H.I.E.L.D.' Season 2 Top Four Spoilers before the Release Date

Jun 26, 2014 10:24 AM EDT

With 'Agents of S.H.I.E.L.D.' Season Two coming back to ABC this fall, the web is abuzz with leaks and spoilers circulating throughout the rumor mill. Before you read on, be warned for there are spoilers ahead.

Here are the top five highlights that have surfaced so far:

The Mystery Cube

At the conclusion of the first season, the SHIELD agency is in shambles following a devastating attack by villainous HYDRA infiltrators. Events leading up to the season finale happen to coincide with the plot of 'Captain America: The Winter Soldier', in which S.H.I.E.L.D. Director Nick Fury (Samuel L. Jackson) apparently dies.

Fury survives the attack though, but decides to go into hiding. In a scene from the Season One finale, the newly-retired government agent turns S.H.I.E.L.D. leadership over to Agent Phil Coulson (Clark Gregg).

 "Before it was torn apart, S.H.I.E.L.D. was a lot of moving parts, but guys like you were the heart" Fury tells Coulson.

"Now, you'll be the head," says Fury before handing Coulson a miniature black box. Nick calls the item a "toolbox" that will rebuild S.H.I.E.L.D. "from scratch."

Using information contained in the box, Coulson brings his team to the 'Playground' -- one of the few remaining S.H.I.E.L.D. bases that have not fallen to HYDRA control. One interesting theory amongst fans is that box also contains a list of new recruits to replace agents whom have either died or defected over to HYDRA. It is not clear what other secrets the box contains.

What is certain is that the contents of the box will be definitely drive the plot in the following season. Perhaps, we will see more of this mysterious cube in Season Two.

S.H.I.E.L.D. Goes 'Lo-Fi' with Its Technology

Up until the HYDRA attack, S.H.I.E.L.D was a massive organization that had a massive arsenal of advanced technology and weaponry at its disposal. In the second season, the new S.H.I.E.L.D. has been labeled a terrorist organization that is no different from HYDRA, and now has to fend for itself without the budget it once enjoyed.

Essentially, S.H.I.E.L.D. will have to fall back on basic hardware and employ good old-fashioned spycraft to finish its missions. Agent Coulson actor, Clark Gregg, shared his thoughts about this in an earlier interview with Collider.

 "It's gonna be 'lo-fi'," Gregg said to Collider. "You're going back to basics, [and] you've got to rebuild S.H.I.E.L.D. from the ground up in a much more dangerous world, where your group is outlawed."

"So, it feels like the early Sean Connery James Bond with brass knuckles and not afraid to knock somebody off," Gregg adds.

During Season One, Agent Coulson and his team gain access to 1940s-vintage gadgetry provided by Agent Antoine Triplett -- who also happens to the descendent of a 'Howling Commando'.

According to Marvel canon, the 'Howling Commandos' were the WWII-predecessors of the modern S.H.I.E.L.D. agency. Citing Triplett's African-American ethnicity, fans have speculated whether Triplett's grandfather is Gabe Jones.

Agent Carter Prequel Spin-Off

ABC network will launch the Agent Carter spin-off in January 2015, during the mid-season break of 'Agents of S.H.I.E.L.D.' Season Two.  The eight-episode prequel series covers the post-WWII exploits of Agent Peggy Carter (Haley Atwell), the love interest of Captain America.

Following events from her own Marvel-exclusive short film, Agent Carter has been recruited to co-head the newly-minted S.H.I.E.L.D. organization. Despite her exemplary wartime service, Agent Carter still has to deal with workplace sexism that is prevalent in the 1940s male-dominant spy agency. Meanwhile, S.H.I.E.L.D. will confront forces that threaten global security.

The narrative of this prequel will coincide with the plot of 'Agents of S.H.I.E.L.D.'

Antoine Triplett Might Cameo on the Upcoming 'Avengers 2' Film

B.J. Britt, who plays Agent Antoine Triplett, was recently spotted on the film set of Avengers: Age of Ultron.  Fans have begun speculating that Triplett will make a cameo in the upcoming Marvel feature film.

Marvel has already introduced into the S.H.I.E.L.D. TV series a variety of characters from the previous films including Lady Sif of Asgardia (Jaimie Alexander), Agent Maria Hill (Cobie Smulders), and Nick Fury (Samuel L. Jackson). Hence, an 'Agents of Shield' crossover with the second Avengers film only seems natural.

Though its exact premiere date remains unknown, Marvel's 'Agents of S.H.I.E.L.D.' will be coming back on ABC at the Tuesday 9 pm EST timeslot.