Disclaimer: Neither Doctor Who nor The Avengers belong to me (unfortunately) nor do Rose Tyler nor Loki (even more unfortunate). The story is mostly inspired by White Collar and this series doesn't belong to me either (as you could have easily guess). All the aliases used in the story are references to Billie and Tom's other roles in their acting career and belong to whom it might belong.
Summary: She's a SIS agent. He's the best conman Great Britain has even known. No one has ever caught him, no matter how hard they tried. He's a challenge. Her challenge. When she takes the case, she decides to have him at his own game by going under cover. Mission: Bad Wolf. Code Name: Hannah Baxter. Everything scheduled to the second, everything perfectly planned to catch him. But what she didn't expect was to be fascinated by him, between seduction and art thief.
Author's Note: This story began with a graphic I posted on my Tumblr and quickly became a whole story in my head. I will never thank Sam enough for her beta reading. I hope you enjoy the story!

She stood in front of the painting, her head cocked slightly to one side. It was beautiful, she could admit. She bit her lip with concentration, admiring every detail, every brush stroke. She had missed that, she realised while biting on her thumbnail - the calm of a museum and losing herself in a painting. She hadn't visited a museum in years, not since... Not since him. It was their habit, museums and art galleries and running with his hand in hers after touching a sculpture on a bet, the guards coming after them. The taste of memories was bittersweet on her tongue. She missed him too. But it was better missing museums. At least they were still here, waiting for her.

She was so lost in her thoughts she barely realised that someone was now standing next to her, watching the painting too. She glanced at him swiftly, barely a second, before looking back at the canvas. They remained silent, as if each was waiting for the other to talk first, or as if they were respecting the painting so much neither of them wanted to talk at all. After five long minutes – was it that long? she didn't think so – she finally opened her mouth, her words just a whisper.

"It is said that Van Gogh actually hated sunflowers."

"Yes, I watch Doctor Who too."

Her snort rang throughout the room and the guard glared at her. She put her hand in front of her mouth not to make any more sound. He just offered her the ghost of a smile before looking back at the painting.

"I like the intensity of those paintings", he said, "all the shades of yellow he used, it makes the whole thing so real. It would have been impossible a few years earlier, since the pigments didn't exist yet."

"So alive."

"Yet so dead."

"It's beautiful."

"It's majestic."

"Too bad it's a fake."

"Yes ind—sorry, what?"

She walked away, smile on her lips, and she almost chuckled when she heard his footsteps following her. It was almost too easy. She stopped in front of a Cézanne, faking interest in the painting. He stood next to her again, the same look of fake attention for the painting in his eyes.

"The glint on the vase. I mean, it's a really good copy, I understand how the curator could not notice... But still a copy."

"And you are?"

"A fan of your work."

She smiled at him, glad to see he didn't seem surprise, confused, or even lost. Actually she couldn't read his feelings on his face or in his eyes. It was a good thing, she knew, it was a way to protect himself. Her smile widened. He looked at her, really looked at her, from toes to the top of her head, and she saw his features softening.

"Hannah. Hannah Baxter." She held her hand out to him. He shook it almost immediately.

"Loki Odinson. But you already know that, apparently."

She grinned, her tongue touching her teeth. "Such a big fan."

She took care to brush past him as she left, slipping a business card into his pocket. Just before exiting the room, she turned around to look at him. He was still watching her. She smiled again, giving him a lazy salute. He nodded and almost smiled back.

Oh, it was going to be so easy.