(I think the Terminator skull wound up dangling at Jean's hip; Rivina, can you confirm?)

Amaruve, with your perception roll, you notice the eyes of the robotic skill flash red as you approach the door. It might be your imagination, but its jaw almost seemed to open for a brief moment...

You don't have time to explore it further, though, as Cordelia has staggered against Kyo and is clutching her head with one hand. "He's... It's Sagacious. He's definitely inside the castle. He's trying to get into my head, but... I'm still me, but I might not be one hundred in there."

(Confirmed. It's hanging from her belt on some leather thongs tied securely to it's lower jaw.)

Quote from Adaxter >>

(I think the Terminator skull wound up dangling at Jean's hip; Rivina, can you confirm?)

Amaruve, with your perception roll, you notice the eyes of the robotic skill flash red as you approach the door. It might be your imagination, but its jaw almost seemed to open for a brief moment...

You don't have time to explore it further, though, as Cordelia has staggered against Kyo and is clutching her head with one hand. "He's... It's Sagacious. He's definitely inside the castle. He's trying to get into my head, but... I'm still me, but I might not be one hundred in there."

 Perspicacious will move to comfort Cordelia. "Don't let him get to you, Cord. We've got this; we've been through a lot. And we're going to get through this too. Let's take it one step at a time, first, by getting through this door." Turning to the rest of the group, "Does anyone have some ideas about how to open this? Let's not keep this guy waiting."

(OOC I'll use my bonus action to consistently help Cordelia with any mind games from Sagacious.)

(Got it. She failed the initial check that you passed, but you can assist with the subsequent checks that follow)

Tony will size the door up, and, as ki flows through his fists, infusing then with magic, he punches the door.

Amaruve nudges Jean toward the door... A bit reluctantly. The more he thinks about it. Maybe finding another way would be wise. He remembers how difficult the machines had been to handle when they were protecting Sarah... He moves behind a boulder and pears around the edge.

Quote from JcAndD >>

Tony will size the door up, and, as ki flows through his fists, infusing then with magic, he punches the door.

The door rings like a bell and there's a flash of white light. The crystalline script above the door pulses and Tony is flung away from it. 

Take 4 damage, Tony

(Looks like the door isn't a fan...)

A finger rises up from the smoking heap that is Lil’ Big Tony, “Door... hits... back...” Tony gets up and dusts himself off, “Well that plan is shot. Anyone else got an idea?”

Fiorello is so focused on the door that he fails to notice Cordelia's plight. He had been attempting to utilize comprehend languages to read the markings over the door, but, "Unfortunately, it doesn't appear that these glyphs represent a meaningful language, per se. They are decidedly sylvan in nature, and they may simply enact the warding defenses just demonstrated on master Lil' Big, or... Is it possible they reflect some kind of key system? This central indentation, this shallow oval inlaid with this repeating wave pattern, I believe that a face is meant to be placed here... Beyond that, I have no idea how to open this gate."

The "wave pattern" carved into the oval indentation in the center of the gate: 

(Do you all investigate further, try some other stuff, or leave to find another entrance? Time is a factor!)

(I'm just waiting for Jean to post before I go tearing my hair out.)

(Ironically she did post out of character, but didn't try, or refuse, to open the door.)

Jean will try first aligning all of the waves, and if that fails she will try making a spiral pattern from outside in.

(I think you're carrying the key.)

(No hints from the DM this time! However, I will say that, other than Amaruve's perception roll to identify threats, no one has rolled for investigation or indicated that they intend to examine anything...)

The pattern on the door can't be moved... Not a sliding tile puzzle, I'm afraid.

Perspicacious investigates the door for clues to how to open it: 18

"Jean, bring that metal skull thing over here, maybe it fits in this socket..."

"Huh. I was sure those panels would slide." Jean said, frowning.

(Did Jean hear Fiorello's words? If so she'll try the skull)

(You were close enough to Fiorello to hear him. Are you removing the skull's straps?)

(I'm going to assume that Jean takes out the skull just to move this along! I think it's around 2 am her time now, so...)

Jean unhooks the skull from her belt and holds it aloft before the gate. It's eyes flash red, and it begins chattering and buzzing, almost falling from her palm before she deftly secures it with her free hand. 

"BRRRZZZKKKTTT-DDDTKKKTTTTKKKKKKKT!"

Fiorello gasps. Of course: he still has comprehend languages active... "Dear lord! What an absolutely awful thing to say!" He looks at Jean. "I had no idea you were carrying something so foul. What in the air possessed you to hold onto it? Do you have any idea what it just said?"

The skull begins to chatter in its static-speech once again. "!!!!!!KKKKKTTGRrrrzvvvvKKTTKT!" It pauses, then, "ZKKKTTT-DDDTKKKTT"

"Absolutely not. I will do no such- wait. What do you mean? Can you read the glyphs over the door?"

With Fiorello translating, the skull explains that it can decode the glyphs with a little time. Assuming that you agree, it spends roughly 5 minutes scanning the patterned script on the door, with Jean walking it from one side to the next. All the while it speaks in a loud, grating static that causes Fiorello to shudder. "That device- that fiend- is disgusting. I've never heard anything so awful in all my days."

This is what the skull translates:

Quote from AsbestosPenguin >>

Perspicacious investigates the door for clues to how to open it: 19

"Jean, bring that metal skull thing over here, maybe it fits in this socket..."

 (Sorry, I missed this, AP)

Placing the skull in the socket does nothing... However, with your roll, you do discover 4 similar ovals on the door, each with a distinct wave pattern in the shape of a handprint. One is red, one is blue, one is green, and one is yellow. 

(My apologies for how crude this picture is; I need to start sketching things out by hand) 

(Is the voice Arnold Schwarzenegger?)

Tony looks over the handprints, “Huh, got any ideas?”

Cordelia looks up at the gate and muses out loud. "Those patterns look super familiar... Where have I seen them before?"