The elven warrior casually walks over, and making it look entirely effortless, places a boot against the beasts shell and pushes. Lewin made for great moral support, supervising so well it rivalled that of T'chal'fronack'zcinicker‘s. Sloppy scraping of the body against the bricks can be heard as it’s pushed and eventually slides off into the river with a splash. Now there was a clear path across the bridge to the doors ahead.

Kerric:

”Okay, are we ready to move on?” asks Kerric as he crosses the rest of the way over the bridge and listens at the door.

Perception:  18

T'chal'fronack'zcinicker looks a bit aghast at Lewin, and echos mostly to himself, "More than just water?"  

He wipes at his face a few times before looking at their clear path to the door. "Right then, shall someone listen at the door or peak through and see what we're dealing with?"  

Following the pre-requisite ass-kissing/salvaging of his ego, Flux took advantage of T'chal'fronack'zcincker's distraction with overseeing the corpse removal to approach Xalkas and quietly ask for a healing pot or two. "I have my own magical ways of mending flesh, but having a potion or two as a precaution never hurts anyone now." He added, presuming some further encouragement might be needed for his half in particular.

Once he had his prize safetly tucked away, he'd hustle his way across the bridge to join the rest. But pointedly this time, he made sure Kerric (and anyone else of a mind to) stood between him and the door. While awaiting the results of the elf's efforts, he'd utter a small prayer and attune his ears towards catching the echoed confidence of his deity. "Mn... I believe your elven friend there is well ahead of you on that point." He said to the tiefling. 

Xalkas readily hands over two of the potions(removing them from my character sheet)

He puts the rest back and waits anxiously for Kerrics findings as he watches the water. 

Upon a second more careful inspection of the door, Kerric realizes there’s something amiss. While initially everything appeared to be clear, and safe, there was a reason why he felt the need to check again. Though, the moment he placed his ear to the door, he sensed it. While his eyes may not have known what he was looking for, the softest, gentlest arcane hum droned through the surface of the door. There’s a magical glyph upon the door, weaved in through the water cultist symbol that adorns it. He’s lucky placing his ear against the door didn’t trigger it., assuredly peeking through would have. 

Kerric:

Backing away cautiously, Kerric says, “There is a magical ward of some kind on this door—embedded in that Water Cultist Sigil.  Who among us can address such a magical trap?”

Lewin steps forward at Kerric's hesitation. He holds up his hand, palm facing toward the door but not touching it, and closes his eyes. He nonetheless sees through the door to its arcane essence, attempting to detect magical charms or protections or spells on it. 

He then tries to ascertain what methods they could use to bypass or disarm any trap. If it is the type of trap that activates when the door is opened, he looks at whether the group could get out of the way, keep a certain distance, and then he could stand 30 feet away and cause the door to open on its own (through thaumaturgy) if it is not locked, to exhaust any threat.

"Magical ward? Hmm... Must be something extra important behind it then! Though, I take it then that none of you've come across any badges, odd trinkets, obvious keys, or the like from the cultist then?" Flux asks uncertain. If none else speaks up about possess any such things the group can try, then after Lewin at done his test and tried to usher everyone back, Flux clears his throat.

"It comes to my attention that I might have something a little less risky we can try. Now, I won't necessarily be able to do this more than once, but this aughta be worthwhile enough." He said, and barring any disapproval, snapped his fingers and points at the door, "Open Sesame and let all else be omitted." With that, the holy symbol of his patrol god flares into being on the door to powerwash any magic from it before it fades away as well.

-Would be casting (3rd level)Dispel Magic on the door. 
If any spell upon it is higher than 3rd level, here's an ability check: 18. 
(the d4 being from the previous guidance)

Lewin is able to successfully detect that the magic is that of Abjuration.

Positioning himself before the Glyph, Flux points and declares. His words echoe only slightly, then as if seeping into the door, it casts out the magic. Then a gust of wind blows, wafting out a smell of rotting fish and replacing it with a cool fresh breeze. A slow sizzle brings forth a gentle steam, dissipating harmlessly along the ridges of the doors surface.

T'chal'fronack'zcinicker slaps Flux on the back in a moderately good show of camaraderie. "Don't listen to what the others are saying, I knew we made a good choice freeing you." 

He thinks silently about the ward.  Are wards like this something that, if you know the right password, you can get through, or do they seal the passageway.  Arcana check : 14.  He's thinking in his own brain what the chances are that the room beyond could be an active spot for cultists, or is more likely a locked storage room.  Though, looking at the two water spewing mouths, it's rather an extravagant styled storage room.

Kerric:

Watching Lewin's work with appreciation, Kerric says, "Have you succeeded?  Is the magic of the ward dissolved that we may proceed?"

If the answer is yes, then Kerric will go back to his position at the door and prepare to open it once the others are ready.

Flux at first smiled broadly at the show of camaraderie. But after taking even a few moments to play the tiefling's word back again in his head, the smile faltered and even began to fade away. "Wai... What's this about others saying? I thought we cleared the air on any lingering grievences." He asked, yet soon enough had his attention stolen by Kerric. "Uh... a-aye! Whisked away by the salty breath of Valkner himself it has. T'is what all that sizzling there was about." Flux explained.

However, as Kerric went back to open the door, Flux would clasp a hand about his holy symbol and whisper both a word of praise and request for a spot of looking out for a bit longer. After that, he'd give Kerric a nod, confirming his readiness at the very least. 

Now that the glyph was in fact dispelled and the trap cleared, T'chal'fronack'zcinicker thinks on it. He comes to realize that the cultist symbol upon the door was a hint and simple hand gesture could have opened the way. All someone had to do was make the hand sign of the water cult, an “X” of the forefingers, with thumbs overlapping, and the trap would have cleared. But at least they knew what Flux could do!

Kerric takes position at the door with guiding support from Flux at his back. Behind them stood the blind monk, ready with her staff. Even if no one looked Ebele's way, she'd nod to signal she was ready.

Kerric:

Opening the door, Kerric steels his will to deal with whatever may be on the other side.

T'chal'fronack'zcinicker ignores Flux's delayed, follow on question, and instead watches Kerric go for the door handle and open the door. Knowing it may indeed be a well used room, he lifts his loaded crossbow, ready to cover the elf, and tries to keep his distance from the door while finding a good angle to see through the crack as the doorway is opened.

Opening the door with bated breath, there’s this sense of entering a sacred space. A temple. Entering at the south of the room, there’s s twenty-foot-wide moat divides this shrine into northern and southern halves. The moat is 10 feet deep, and the water level is almost even with the floor. However, the smaller spillways that carry water south to the culverts are only 2 feet deep.

In the southern half of the room, two ten-foot-wide channels run along the east and west walls of the shrine, spilling out through low culverts to the south. Two more pillars stand here, and a low stone bridge leads across the dividing channel to the altar and the northern part of the room.

In the north half, two large stone pillars flank an altar in the form of a plain stone block. A few coins lie on the altar. Above and behind the altar looms a huge symbol made from beams of driftwood, fixed in an X-like shape on the wall. A single stone door leads westward from this part of the room.

Five lizardfolk warriors of the Blackmaw tribe stand guard in the southern part of the shrine while a tall amphibious looking humanoid in cultists robes stands next to the altar in the northern part of the room.

All eyes turn to the doorway which just opened. On you.

T'chal'fronack'zcinicker says, just loud enough for only the group to hear, "How long do you think they were standing there like that before we came along?" 

Lewin reaches down and places a hand on T'chal'fronack'zcinicker's shoulder and says, "stay vigilant."

(He confers Vigilant Blessing which allows advantage on the next initiative roll.)

 (Let me know if he gets another action to cast something before something might kick off...)

Kerric:

With nothing really to do other than enter the room, Kerric strides in and says, "I suppose it would be too much to hope that you all are the true followers of the good sea god, and not just more evil Crashing Wave cultists" as he draws his Elven Curved Blade defensively.