ORIGINAL AIR DATE: Feb. 5th, 2015
SYNOPSIS: More Robonoids keep showing up on Earth, driving the Crystal Gems mad. Steven suggest they follow one so they can find out about Homeworld's plans.
Connie introduces Steven to her favorite book series: The Spirit Morph Saga. She geeks out as she explains the premise, ultimately convincing Steven to give it a try, though he does mess up when he reads the books out of order (Connie was not amused.) Their excitement has to wait though, something crashed into the ocean.
It's one of the Robonoids, only this one is ten times as big. The Crystal Gems knock it down, but it does little to evade their concern. Peridot may not be able to use the Galaxy Warp Hub to revisit Earth, but she can still send down probes! Steven is worried, but Garnet assures him the robonoid is destroyed.
Another robonoid arrives the next day, forcing the Crystal Gems to pummel the marble menace once more. Steven wants to know why it's here and what it wants. The Crystal Gems don't have any theories to offer, but at least it's destroyed! The next day, yet another Robonoid appears and yet again, the Crystal Gems are on the offense. Steven steps in and suggest that maybe they should follow the robot and see what it's after. The Crystal Gems are getting tired of fighting every robonoid coming their way, so they agree to try out Steven's plan.
They follow the robonoid to Kindergarten. The Crystal Gems are already creeped out, but with Steven's encouragement, they power through. The robonoid drills underneath the base, leading the team to a large control panel. The robonoid activates the panel so Peridot can access it from the other side. There she can monitor Kindergarten and presumably restart it.
The Crystal Gems formulate a plan to smash the control panel, leaving Steven free to sneak up and actually talk to Peridot to deduce what her plans are. Peridot is intrigued at this "Steven" and asks if the "Stevens" are the dominant species of Earth. Steven tells her humans are still around, but when it's his turn to ask questions, Peridot responds by nearly crushing him with a giant mechanical fist. The Crystal Gems rescue him at the risk of exposing themselves to a homeworld Gem. Peridot is stunned, there's been no records of any Gems living on Earth! Now she knows why her robonoids keep getting destroyed. The episode also reveals the Red Eye last seen in "Laser Light Cannon" was also sent by Peridot to monitor the planet. The Crystal Gems successfully destroy the control panel, but Peridot now knows they exist and that's a whole 'nother ballpark to play in.
Steven admits he overstepped his boundaries, but Garnet said they did learn something new after all. ...He still screwed up though.
It seems hasty and forward of the Crystal Gems to spend much of "Marble Madness" just smashing the fancy Homeworld gadgets than pondering the long term effects this would have. It feels like a contrived way to get Steven involved in the greater narrative and offer a solution so he isn't just a kid watching the whole thing. There are reasons for the Crystal Gems' actions that may justify their outward violence though. Peridot complains that Earth's Kindergarten control panel is "archaic", indicating Homeworld has vastly upgraded their technology in the past 5,000+ years. The Crystal Gems don't know what the robonoid is and what it can do, so imagine the weapons Homeworld has since created. They should be so lucky that all Homeworld sent so far were a bunch of monitors. The Crystal Gems are also in a state of panic because they're horrified that they could be forced to relieve another war. This is something they can't afford. They don't have Rose nor other Gems allies. It's literally just the three of them and Steven versus an entire stronghold. Lastly, the Gems simply cannot give off any hint or indicator that they live on Earth, otherwise Homeworld really will have a reason to send even bigger threats to eliminate them and possibly reactivate Kindergarten and that will spell certain doom for Earth.
Their actions are understandable when you see it with context. Garnet and Pearl struggled through a war that ended with numerous sacrifices and an equal ton of emotional baggage. "Marble Madness" is a quietly intense episode and Homeworld's presence has only increased the urgency. Time is running out for the Crystal Gems.
...It's still a little contrived though.