Based off of gifset post/72153821975/captain-swan-au-siren-emma-on-his-quest-to
"It's all for emma. It's all for Emma." Killian repeated his mantra to himself as he traversed over bramble and stone towards Lake Nostos. As per advice from David, the magical water should heal Emma's memory, once he found her. Hook would need backup if his original plan failed. Killian picked up his already brisk pace at the thought or seeing her again. He knew he must, and he knew he would. Nothing could keep him permanently away from his Swan. Not even a pesky siren.
Oh how he missed the motion of her lips on his, the way the sun kissed her hair, and the ever bright fire in her eyes. He had not seen his Swan in quite sometime, and he counted the days with misery. Killian was nervous that each moment that passed took him farther and farther from regaining his beloved's memories.
When Cora had brought back the water in Lake Nostos, naturally, all the life nearby resumed its grandness. Even the Siren that David had thought to be dead. The sun itself was barely kissing the horizon, and it cast the lake in a lazy purple hue. Calm as could be, eerie beyond a doubt, and silent. Killian wasn't sure what that meant. Shuffling over to the periphery of the lagoon, he filled his flask up to the cusp.
"Are you sure you want to be doing that," he heard a feminine voice call. Glancing upwards, Killian saw a woman with platinum blonde hair stalking towards him.
He would not let himself be subdued by this creature. He must get back to Emma. "I must return to my love, and this water is the key element," he drawled in with a light brogue.
"Why waste your time, with the chance that she won't even accept you? Why don't you just stay here with me?" Her voice did not ignite anything in Killian's soul, as Emma did. He could never stay here, while his heart belonged to another. The sun's remaining life was draining from the sky, darkness starting to envelope the glade.
Her proximity was imminent, and Hook could see that she was metamorphosing into a form he had learned to love. Her sterling eyes gave way to a resplendent, veridian color, and her frosted hair seemed to suddenly put the sun to shame. She looked just like her. Oh Gods, he thought to himself, it's Emma. Right in front of me. But she didn't look quite right. She was still the Siren at her heart. Snap out of it mate! This is not your Love. This creature is here to impede your quest. Snap out of it! "Flee woman! I will not fall prey to a siren! I will return to my true love!" He bellowed at the woman a mere foot from him.
It damaged him though, to see her in front of him like this, whether or not she had a death wish for him. He wanted nothing more at that moment than to hold her and forget that Emma had no clue as to who he was and remembered nothing of their shared past. She looked fixedly at him, her sight boring into his soul. Killian's resolve was becoming weaker and weaker, losing his will to fight the siren as she took him close to her, and delicately placed her lips on his. Her touch lingered gracefully, and the pain in his chest suddenly exploded into a torrent of need, pain, and weakness. He grabbed Emma's doppelgänger and hastened the kiss.
Moments after Killian had engaged, he felt off. He did not feel as he had in Neverland, when Emma had initiated their kiss. The exchange felt empty, and he knew it was not her. Emma was in a distant realm, without her memories, and without him. His mind screamed to him, Fool! This is not your love! Love like this does not feel empty and purposeless. Leave, now! You have what you came for, now begone! Don't fall prey like those before you! Killian did not want empty, physical sensation. He wanted reality. He wanted to hold Emma truly, and to love her only.
The Siren broke the kiss, and cooed in the captain's ear,"well captain, still believe you would not like to stay? I can assure you are anything other than prey," she hissed out the last part as metal scathing metal broke the otherwise silent air. She attempted to put as much as space possible between herself and Killian, but his hook said otherwise.
Killian drew the skinny blade into the air while commenting to the doppelgänger as she struggled, "see darling, I would love to continue the dalliance we have going on here, but I've got to get back to the woman that I share true love with, not her mere look alike." And with that, he swiftly slid the dagger into the maiden's heart, only to hear her utter a short whimper before she fell lifeless into the crystal waters. Her appearance reversed, and her opaque eyes stared above at Killian as she her heart bloomed ribbons of vermillion.