'The 100' season 4 spoilers, plot news: Grounders using radio tech?

The Grounders will be using radio technology when "The 100" season 4 airs on The CW. This has been revealed recently based on an Instagram photo posted by the Writers Room.

The post features a drawing of a radio and comes with the caption, "Radios are NOT your friends."

This led to speculations that perhaps someone on the enemy's side of the Grounders will have access to one and is going to use it to spy on someone and hopefully intercept some crucial intelligence as messages are passed back and forth. The image also gave pause to consider whether the Grounders will embrace a new faith or will alter their old beliefs with regard to technology.

As followers of the doubtless know, Grounders do not use any form of technology. The image implies that this form of technology will be present in their midst. If they are not using it, or do not believe in its use, it could be that the Sky People are spying on each other.

This ties in to another theory that some dissension or schism could occur among the Sky Crew. This could only reassert the long held conviction that technology cannot be counted on, after all that has transpired with the A.L.I.E.

Yet, this is not all the trouble in store for the upcoming season of "The 100." At Friday's San Diego Comic Con, Jason Rothenberg, the show's creator, along with the cast, teased a bit of what viewers can expect in the next run.

A short preview was played at the event, giving a glimpse of Polis in a dark haze of a nuclear fallout. The narration described the new enemy that the world would be facing, one that "isn't something that can be fought" or "reasoned with," Clarke (Eliza Taylor) narrated. And a few choice questions at the end are food for thought.

"When all is lost, can hope survive? Can we survive? After everything we've done, do we deserve to?"

Rothenberg explained what the enemy would be: "The earth strikes back in Season 4, it is an unbeatable foe."

Survival is the thing next season. But without enough options for escape, who gets to decide who lives or dies? Clarke will be taking on the reins of power once more. But how will she save the world this time?

"The 100" season 4 will premiere sometime in 2017.