A/N: Season 3 spoilers. I do not own the Flash or associated characters, they are the property of the CW and DC Comics. I just think that Earth-2 is underutilized, and when I noticed that both Earths had a "Detective West" lose an immediate family member because of a Killer Frost/Evil Speedster team-up...
He met her by accident, at a hole-in-the-wall bar that didn't exist on Earth-1. He needed space to grieve, so he'd asked Wally to take him through the breach, to a place that didn't remind him of what he'd lost with every step. She was sitting at the bar, cradling a whiskey, when she happened to look up and notice him. He froze, transfixed by her too-familiar face.
(She'd been working a tough case, one involving a dead lounge singer who reminded her too damn much of him. She'd sent Barry home alone and gone out to try and drink away the memories. Things had been mostly quiet on the meta front since Zoom's empire had collapsed and the new Flash had helped round up the remnants, so she could afford to give herself a break. He walked through the door and she cursed herself for ever thinking that things could be peaceful.)
He should have realized there was a chance she'd be here. This was Earth-2, of course she was alive and well here, Barry and Cisco had met her. She had the life his daughter should have had, a happy marriage and a stable job and no psychotic time travelers to stab her in the back.
(He couldn't be here; her dad was dead. If this was some kind of shapeshifter who had managed to get around her metahuman detector she would make them regret it. She drew her gun on him.
"Freeze! Police!")
He raised his hands slowly. "I'm so sorry," he said, and he knew she wasn't his Iris but she looked just like her, down to the look of angry determination. "I just needed to get away, so I asked Wally to- I didn't realize you would be here. I'm so sorry, baby girl."
(She finally managed to gather, through the tears and half-sentences, that he was from Earth-1, like that other Barry who was the Flash. She was also pretty sure, although he didn't say anything, that something terrible had just happened to her alternate. "Sit down," she said, patting the next barstool. "You look like you seriously need a drink.")
"She was amazing," he said, after downing the first two glasses. "My baby girl, all grown up. She was the best of us, so smart, and so caring. She always made sure we were okay, never worried about herself. I just can't believe-" He broke off, unable to speak through the tightness in his throat, and finished his drink.
("My dad was a singer," she said. "He didn't want me to be a cop, and he didn't understand it, but he supported me the whole way. Even when Zoom took over, I sort of thought he'd always be around.")
"... and she walks through the door, absolutely covered in mud, and tries to convince me that she had nothing to do with it!" he laughed, several hours in. It felt good to laugh, with this woman who wasn't his daughter. She grinned back and started in on a story about a similar incident from her childhood, except that this one involved a bucket of glue and a live blue jay.
("I loved my dad, and I miss him so much, but he had no idea what it was like to watch my partner die like that! And he never understood what I saw in Barry, and I just wish they could have gotten along, because they were the two most important people in my life." The man who wasn't her dad held out his arms and let her pull him into a tight hug. It felt just like one of her dad's hugs.)
They met up again the next week, and the week after that. Their meetings were a source of constancy amid the chaos that his life had become.
(It was a chance to celebrate the people they had lost and to mourn the things that they would never have. He introduced her to the brother she had never known and she hugged them both so tightly that Wally claimed he couldn't breathe.)
She wasn't his daughter
(He wasn't her father)
but Detective West was everything that Iris could have been.
(But Detective West understood her in a way that Joe never could.)
She wasn't his daughter, but spending time with her helped him keep going.
(He wasn't her father, but sometimes it felt better to pretend.)