Klaus' Daughter is a Lockwood?

Rebekah & Nicole's discovery

 It's morning; Klaus enters Hayley's room while she's still sleeping. He watches her for a moment, then reaches into her bag, withdrawing from it the vial of wolfs bane. He opens it and lifts it to his nose to smell, when Hayley speaks. "I didn't use it." Klaus looks at her. "You're awake." Hayley yawned. "I could barely sleep all night. This house is like a freaking swamp sauna." She sits up in bed while Klaus stares out the window. "What stopped you? You could have been free of all of this... of me." Hayley shrugged. "Yeah, well... when I was fighting off those vampires, I – I realized I wasn't just protecting myself. Maybe it has to do with the fact that my birth parents gave me up, and my adopted parents kicked me out. All I know is push came to shove, and... I realized I wouldn't let anyone hurt it." Klaus smiled slightly. "I'm beginning to think we're a lot alike, you and I. We're both castoffs who have learned to fight when we're backed into a corner." Hayley nodded. "Well, we're backed into a corner now." Klaus sighed. "Ah, that we are. It's time to fight... little wolf." After gently placing a hand on Hayley's shoulder, Klaus backs away and moves to leave. Hayley speak before he can leave. "This whole thing with Marcel – the deal you have with the witches, trying to take him down, take what's his – Rebekah told me that you two once loved each other like family. What happened?" Nicole over heard them talking and started eavesdropping. She needed to understand who Marcel was and who she was up against.

Klaus' face hardened. "I made Marcel everything that he is. I treated him like a son. And when my father chased me and my family from New Orleans a hundred years ago, we believed Marcel was killed – we each mourned him, in our own way. Yet, when I returned, I found not only had he survived, he had thrived." Nicole felt terrible for her father. Klaus continued. "Instead of seeking us out, instead of sticking together as one, he made a choice to take everything my family had built and make it his own. Now, he is living in our home, he is sleeping in our beds. That 'M' he stamps everywhere... it's not for 'Marcel'. It's for 'Mikaelson'. I want it all back, and if I have to push him out to get it, then that's exactly what I'll do. I'll have someone see to the air conditioning." Nicole pretended to be walking out of her room as Klaus exited Hayley's. "it not polite to eavesdrop love." Nicole stopped dead in her tacks and her eyes widened. "How did you know?" Klaus smirked. "You're not as stealthy as you think you are."

Klaus and Nicole hurry down the stairs, only to meet Rebekah as she enters the front door. "You were right. The girl, Cami – she's the key. Marcel likes her, and because of that I got to see the secret weapon of his that you've been going on about."He smirked. "yes Nicole told us when she returned home last night. It's a witch." Rebekah continued. "She's not just any witch, she's something I've never seen before, something beyond powerful, and now because of you she has Elijah. Who knows what she could do to him." Nicole was scared for her uncle. She saw how powerful Davina was. "We need to get Elijah out immediately." Nicole said. Klaus turned to Rebekah."Where is she?" Rebekah stops to think, then looks confounded. "That clever bitch. I don't know." Klaus looks at her questioningly. "What's wrong?"

Rebekah sighed and threw her hands up in defeat. "She wiped my memory of the location." Klaus looks to Nicole. "Do you remember?" Nicole thinks and tries to remember. "All I remember is her and Elijah being in his coffin." Rebekah shakes her head and charges at Klaus. "Great! Marcel possesses a weapon bigger and more powerful than an Original, and you handed our brother to him! How many times will Elijah forgive you? How long until his hope for your redemption finally dies?" Klaus yelled at her as Nicole stepped in front of him to keep him away from Rebekah. "I did what I had to do! Marcel took our home!" Rebekah yelled back. "And our home is worthless without family. I am finding Elijah – whatever it takes. Are you going to help me?" Nicole nodded. "I'm in." Klaus nodded. "Whatever it takes."