Peri:

He returns to the others. "Nothin' doin'. It's just a big hilltop up there; no doors, no windows, not even a chimney. Unless you can think of a way to get those doors open, I think we've gotten all we're gonna get here."

Kei 

The casting of his spell to aid Peri ends his Invisibility early. He floats in place while Peri scales the slick cliff. He scans the surrounding area, both above and below as best he can. Minutes pass and then he hears an almost inaudible splash. Peri returns to the group. 

With Peri's report Kei chimes in "Well, we have something at least. A presumably disabled net and knowledge that these brutes are tougher than expected. Guess we call for our ride?" His eagerness to leave and return to dry land evident. 

Gerrard:

”Unless someone has powerful magic to open or bypass the main door, I would concur, Master Fenwader,” says Gerrard.  

“Mistress Boko,” he adds, tuning to her, “Do you have an idea for another animal form that you might take once we rest to scout some more?  Bypassing this main door seems almost impossible without magic or an unlikely deceptive ploy.”

"Did ya touch tha door? Try ta open it or did ya just look at it from afar an' make up yer mind?" Qivys asks. 

(The large stone doors are set into the vertical rock surface, each ten feet high and five feet wide. The surface of the doors is featureless, with no visible handles, except for a rectangular aperture six inches wide by four inches high cut in the center of the left-hand door, about six feet above ground level. A flat metal plate covers this aperture from the inside.)

As you watch, they suddenly open. A pair of sahuagin emerge, and without looking around, begin to head across the stone causeway toward the marsh. You get a quick glimpse of a handful of sahuagin within, who soon close the door again.

Peri:

"Did I touch the door?! No! I wasn't plannin' on waltzin' in through the front door. I don't think they're inclined to receive visitors."

Just then, as though conjured by their discussion, the doors open. Peri watches the sahuagin pass along the causeway. "We could follow those two and find their guard post, assumin' they're relievin' a watch and not just out on patrol."

Kei 

"If you want deception, all you need do is ask." Kei seems to rise a few extra inches out of the water as he puffs his chest. "These things HATE the Sea Elves, yes? I can easily make a pair of Elves appear at the end of the causeway. That may cause them to all run across and  try to attack them. That might give us time to enter unseen if we were to climb up the wall or be hidden along the side of the walkway itself." He pauses a moment to let the group digest his plan before continuing "Only thing is, if we fail - we die. If we succeed - we raise their alertness for the upcoming attack"

"What's tha thickness of tha door?" Qivys starts his questions. "What's it made of? Could it be breached? Was there murder holes in it?, If'n an assault is gonna be conducted against these beasts I'd hate ta lead a platoon of men inta an area where tha scouts were sent but got no infermation ta share. "

Qivys goes silent and strokes his beard.

"Alright" he finally says. "This ain't tha place ta do this." 
Qivys starts looking at the shore line as far as he can see. 

@DM

Gerrard:

”You are right, Master Qivys.  Let’s follow the patrol and see what we find…by the time they return for shift change we can hopefully have a cogent plan for sneaking in the front door,” agrees Gerrard, whispering and keeping his head low.

The two sahuagin casually begin to cross the 190' stone causeway to the small headland at the river mouth, at the edge of the marsh. The party is treading frigid water in the dark, resisting the sluggish pull of the river outflow. You can follow the sahuagin and keep eyes on them for a while, but some of you may have trouble keeping pace swimming for those first 190 feet. 

(How long has it been since we started our floating short rest? Is Boko at all close to being rested and able to wildshape again?)

(No short rest quite yet. Another 15-30 minutes to go. The cold is also starting to creep into the bones of those who are not naturally water folk or cold-resistant, even with the warm waterwear.)

Kei 

Annoyed that another of his extraordinary plans is shelved he mutters to himself "They'll see it has merit". He casually begins to swim towards the shore briefly looking over his shoulder at the group. "Well? Are we going to do something? We can't just float here and watch those two just disappear." Then in his mind Maybe I should suggest we stay here then everyone will want to swim ashore. He looks back to the coast and tries to spot the easiest place to make landfall.

Qivys heads towards anyplace he can get his feet on solid ground. 

The group begins to swim parallel to (but at a safe distance from) the causeway. The sahuagin disappear down a path through the dunes into the marsh as the party (or at least those who join the shore party) makes landfall on a narrow, foul-smelling beach between the river and the headland where the causeway ends. You have lost sight of the sahuagin, but you expect they can't be too far ahead.

Gerrard:

"Let's follow them before they get too far ahead," says Gerrard, slinking onto shore and trying to keep his head down and move quietly along the sahuagin's path.  Knowing his own weaknesses, he hopes someone more perceptive will lead the way...

Stealth if needed:  23

Peri:

Peri bites back a retort to Qivys's criticism. Instead, he sinks back down beneath the waves and swims as quickly as he can to the end of the causeway. Poking his head above water, he looks around for any sign of which direction the two guards have gone.

Stealth: 23 (+10 if Pass Without Trace is still running)
Perception: 15

Boko has been quiet during this waiting period - she ritually cast speak with animals and spent some time asking any small critters and fish that live around the causeway what they have seen recently. Do the sahuagin come out a lot, do they patrol underwater, under the causeway, does anything else come by, what happens at night vs the daytime, etc.

She keeps talking quietly in chitters and bubbles and faint squeaks as the group moves along. She stays under the waves for longer, until they get close to shore.

Then she pops up and tries to hone in on where the sahuagin went.

Survival: 21

Stealth: 25

Qivys makes his way to shore then stows his helmet. He will start making his way to the location of those Sahaugin, the best he can estimate. 

Kei 

With the group finally moving ashore, kei clambers up the beach. He takes a moment to catch his breath and then slowly stands. He rubs at the base of his neck as if he's been bitten by sea lice or some other aquatic parasite. 

As the others begin to emerge from the choppy waters he gathers his shield in front of him and searches for a path leading on the direction of the sahuagin. "This way" he states bluntly, still a little peeved.

Perception Unable to parse dice roll.