This includes a spoiler for "The Romance Resonance," but honestly, not really. Even reading this fic after seeing the episode, you might not know what the spoiler is until you read my author note at the end. Basically, if you haven't seen the ep, just avoid my A/N at the bottom and you're good.

Oh right, the thing about me not owning anything.

"I have a present for you!" Leonard said cheerfully as he entered the apartment.

Penny looked up from the magazine. "Oooh," she said. A present from Target! Whatever could it be?"

Leonard sank down on the couch next to her. "I was thinking about our conversation last night. About my leaving soon."

Penny sighed. "Right."

"I don't want you to go," Penny said. "And I know you know that, and I'm not trying to stop you, but…but I really just…" she trailed off, looking down at where her hands rested on his chest. She looked up, her voice cracking. "Leonard, you know how much I hate change."

"You hate commitment," Leonard said. "You tell Sheldon that change is good."

Penny shrugged. "You leaving is not a good kind of change."

"You told me once that Catcher in the Rye was the one book you actually enjoyed in high school," he said. "Right?"

Penny cocked her head. "Yeah. Why?"

"Do you remember," he said, putting his hands on her shoulders and easing her down onto the bar stool, "how Holden didn't like change?"

"Well, yeah," Penny said. "His brother died. That's a change. People going away. A change." She shook her head. "Leonard, Allie went away because he died, you're not making me feel better here."

"But remember the ducks?" Leonard said.

A smile came over Penny's face. "They go away, they migrate, but they always came back."

Leonard nodded. "Some change – even sad change – is inevitable, it has to happen, but it doesn't last forever."

"I still don't want the ducks to migrate," Penny said.

Leonard smiled. "That's still a few days away."

"One day closer," Penny said.

"I know," Leonard said. "But here."

He handed her the bag, and she took it, peering inside curiously. A smile came over her face as she reached inside and drew the object out. "A rubber duck."

"Yep," Leonard said. "And if you're ever particularly sad that we're apart, just look at that cute little duck, and remember that I'll always come back."

Penny turned the duck over in her hands, then leaned over and kissed him. "Sounds good."

So I noticed in that box of stuff that Penny had, there was a rubber duck in it, meaning at some point Leonard had given her one. And as Kaley's character in 8 Simple Rules loved Catcher in the Rye (even though she was not interested in schooling at all), and there was duck symbolism in that book, I decided to use that as the basis for why he gets her a rubber duck.