He was different. She knew that from the day she met him at the airport and he had given her that cheeky little smirk.

She had tried to set him on fire.

She didn't believe in the tests, at first. The trials had been real, they had happened. Cortexiphan. It did roll pleasingly off the tongue. And apparently, into the blood-streams of hapless young children.

He had glared at her disapprovingly.

The lights had gone out. Somehow. Just in time, the lights had flickered out one after another, just like magic. She had turned, shaking, and he was there watching her with a slight smile.

He had taken her hand and she had stopped burning him as he crouched in front of her with a small smirk on his lips as he felt her indignation.

Mirror universes. She should have known.

The images he showed her were wrong, ever-so-slightly.

Peter had always been different. Perhaps things would have been different if he had never been this Peter Bishop. This Peter Bishop died of illness, had meant to stay dead. Perhaps Cortexiphan wouldn't have found its way into Olivia Dunham. Or maybe it would have gone horribly wrong all those years ago in that room burnt to charcoal.

This Peter Bishop had taken her hand and shown her his life, just slightly different from her world. He had smirked at her surprise, laughed at her anger, and lent her his control. They were the perfect pair, Olive and her looking-glass partner.

Even without her memories, she knows there's something different about Peter Bishop.