1x13 – when Harrison suggests killing Ronnie, Caitlin becomes his voice of conscience without even trying
The moment this atrocious suggestion left his mouth, he locked his eyes with the woman he loved, not in the least afraid of how she might respond, meeting her gaze bravely, almost challenging her to defy him.
At first, she didn't say anything else beside the all-too-expected 'this wouldn't be right' and 'there had to be another way', but as soon as the boys disappeared, she turned straight to him with a menacing, "Don't make this personal, Harrison."
He couldn't help but immediately flicker his blues to her, curious to where she was going with this.
"I never pegged you for an insecure man," she continued when folding her arms over her chest and shooting him a belligerent look. "I am with you. It was always you before him, don't you remember?"
He was just about to say something, anything, but in the end he changed his mind. They both seemed to know that if they didn't come up with a solution to help Ronnie, he would explode, putting the entire city in jeopardy and then not only he would die, but everyone else as well.
"Crude weapon, dr. Wells, if I may," Gideon pointed out when Harrison grabbed a gun from his time vault, taking the safety off and checking for bullets.
"Agreed, Gideon, but it will do the job," he said and then actually hesitated, staring at the cold metal in his hand, hating the said crudeness of it just like his AI mentioned. She knew him all too well, actually – or was rather programmed to.
In the end, he put the gun away and covered his face with his hands, releasing a deep sigh. Caitlin Snow had a very bad influence on him, he decided. She was in love with him and they were both painfully aware of the fact, their hidden – so far – relationship a testament to that. In fact, it'd all stared long before the accelerator explosion and despite her going on a few dates with Ronnie, Harrison had never been jealous, knowing well that in the end she wouldn't be able to resist the pull of the darkness that was him. In the end, she wouldn't even let Ronnie touch her, much less kiss her and he was right, welcoming her back into his arms with deep satisfaction, read to take her over and over again. Their relationship was intense, stormy, powerful. He knew she would never be able to start a normal life with Raymond no matter how good that might be for her in the end. Because she didn't want good. She wanted him, Harrison Wells. Or maybe rather Eobard Thawne, he smirked under his breath.
So no, in the end killing Ronnie wasn't personal. It wasn't that he wanted the man dead because of his obvious affection for the woman he was with. He knew he would always win that fight, because as Caitlin said – it was always him before Raymond.
This was an entirely different manner. If he let Raymond explode, all of the people in the city, including the Flash he was training, the woman he loved and the boy he treated like a son, would die.
And he couldn't let that happen.
Then his eyes set on the stolen from Mercury Labs device still attached to his suit.
Yes, Caitlin Snow had a really bad influence on him, indeed, if he was actually considering saving Raymond with this.
And it went both ways, because he was the darkness to her light. She was making him soft whereas he corrupted her. Yet, he knew she was trying to desperately hold onto the good that was still there inside of her, not able to let that go entirely, not able to let herself drown in the darkness just like he, Thawne, had. Killing Ronnie would only push her deeper into it and surprisingly, Harrison didn't want that fate for her. He loved her inner light, he craved it, was drawn to it like a moth to a flame. He, who'd never experienced love before, all he'd known being fear and rejection and hate. He refused to change her if he had a say in it. She was too good for him. She would always be too good for him and she was what he needed. The one good, pure person in the entirety of all the timelines and multiverse, who'd somehow chosen to love him.
In the end, he made his decision. He would try and save the man. For her. And maybe for a change she would make him a better man instead of him constantly corrupting what good was left in her.