A splash of water

The slight breeze chilled her to the bone, as she made her way over the cobblestone path. Her footsteps resounded in the empty streets. The moon was already low, gleeming over the cold ocean in the distance.
Lauren clenched her ragged linnen cloak tight, although it did not do much for her against the cold. Her breath formed little cloudy puffs in the air as she sped towards the harbour. Tension made her heart beat faster than her fast footsteps ever could.

This has got to work.
Her face turned grim as she picked up her pace as fast as she could.

...

Lauren sat down on slippery rocks just outside the harbour. No one should see her here, but she remained carefull. There were some sailors in the distance, drunk and singing. No threat for her.
She leaned forward and gently slipped her arm into the cold sea. A  slippery hand closed around her wrist in the murky water. Her heart nearly jumped out of her chest, Lauren started to pant a little bit.
A shadow emerged from the water, with eyes gleeming white in the light of the distant harbour. When it started to speak, the voice sounded soft and as if a thousand snakes were hissing.

"I know what you want. I demand payment."
The song of Eire in that voice made Lauren homesick.

She felt little tears forming in her eyes.

"I know," she sighed, "and I am ready to make the deal."

"So'll be it. A life, for a life," the creature hissed, tightening her grip around Laurens wrist. It hurted so much, as if little hooks clawed their way into her skin.
Lauren smelled the faint smell of her blood in the crisp air. Little slurries of fog surrounded them, as if to conceal them even more in the dark.

"Then it is done," the creature hissed, releasing Lauren from her tight grip and showing her hand which was covered in Laurens blood. "Sealed in your blood, this deal."
Lauren started to sob, the grief over what she had to do was simply too great. Her sobbing turned into loud coughing.
Her lungs burned, and she spat out some blood. Nothing new for her there, only the confirmation the end was in sight.
The creature emerged a little bit more and tilted her head, as if in wondering. The shadow seemed different from before, even her eyes had a darker tone to them.

"It will be alright, Lauren," the creature spoke friendly. "I will take care of your husband. As long as he has the sprite in the vessel, all be right. In time."
Chills dripped down her spine as Lauren recognized her own voice, emerging from another mouth. It was as if looking into a dark mirror. She quivered, but reminded herself of the deal she made.

"Stay with me until sunrise?" she asked, and her dark reflection nodded in the black water.

It was march 17, 1838.