"I presume you are ready, then. Take my hands, link hands with those who are accompanying you, hold your breath, and most importantly, don't let go." Liliana takes Cygna's and Heims' hands, and in a moment they find themselves underwater.
Cygna is shocked by the sensation of freezing cold water overtaking her, and struggles to suppress the reflex to gasp. The air in her lungs burns with the shock to her CNS, and she chokes a bit and sucks in cold salt water.
Heims, being naturally cold to the touch, doesn't even notice the temperature of the water. Feels just fine to him-- heated bathwater probably scalds him a bit, but this water feels just right to his body temperature (Because he doesn't experience any temperature shock, he doesn't need to make any Swim+Stam rolls to keep his breath held.)
You are underwater for less than half a minute (though to Cygna, it feels like an eternity) before the group re-surfaces. As you look around, it seems that you're still at the covenant-- you're in the marsh, and the lighthouse is just there-- only after a moment it becomes apparent that this is a slightly different lighthouse, and the Great Hall is missing. "Welcome to Flint," Liliana intones emotionlessly. She holds your hands as she walks the group to the shore, and as she releases your hands, everyone except Hiems becomes magically dry. She leans forward, presses something small into his hand, and whispers into Hiems' ear, "Your Parma is formidable; I cannot dry your clothing and hair. Keep this sapphire with you; keep it safe and dry. When you are ready to return, simply wet it with your own water-- if you willingly place your own blood or saliva upon the stone, I will be able to locate you, wherever you are, excepting Heaven or Hell." Without any further ado, she takes a few steps into the marsh, and promptly vanishes as if having dropped into a sinkhole.