They drove along in silence, the tension palpable. After a while, Penny's phone pinged and she began texting busily, as Leonard winced with irritation. Then she dialed a number, only to hang up quickly.

"Leonard," Penny said, "we need to go back."

Leonard sighed.

"Penny, look: I know I screwed up, yet again. And I understand if you don't want to get married tonight. But can't we at least try to have a nice weekend in Vegas?"

"That's not it," Penny scowled. "You're right, you screwed up. And probably we shouldn't get married right now. But that's not why we need to go back."

"Why, then?" Leonard asked, now curious.

"Listen to this conversation I just had with Amy," Penny said with a worried tone, and read to him:

Amy: Penny, can you come over? I really need to talk to someone.

Penny: Didn't Sheldon tell you? Leonard and I are on our way to Las Vegas to get married, or maybe not.

Amy: Sheldon and I aren't speaking. I told him tonight that I need some time apart to think about our relationship. Now I'm confused and upset and I really need to talk to someone.

Penny: Is Bernadette around?

Amy: She and Howard took Stuart to a movie for his birthday. I really want to talk to you.

Penny: I'll call you right now.

Amy: Forget it. It really doesn't matter anymore.

Penny: Let me call you now.

Amy: Please don't. I deserve to be alone. Goodbye, Bestie.

"Whoa," said Leonard. "That's pretty dramatic, even for Amy. Did you try to call her?"

"It went right to voicemail. And did you notice something else?"

"What?" asked Leonard.

"I texted her that we were going to get married and she didn't even mention it. That's not like Amy. I'm worried. I think we need to check on her."

"OK," said Leonard, secretly relieved that they now had something to focus on together. He pulled his phone out of his pocket and handed it to Penny.

"Let's text Sheldon."

Penny found the number and waited.

He dictated: "Hey buddy, Amy told Penny what happened. I wanted to check in to see how you're doing. I'm here for you if you need somebody to talk to."

"Aren't you going to mention that we're concerned about Amy?" Penny asked, annoyed.

"That would just scare him off," Leonard explained. "First I have to get him to talk to me."

Meanwhile Leonard was slowing down to take the exit. They wound through the underpass and got back onto I-15 headed toward Los Angeles.

They waited a few minutes, but no response. Leonard looked troubled.

"It's only 10 on a Friday night, I know he's up. Call the apartment."

Penny called, but voicemail picked up on the fourth ring.

"Should I leave a message?" Penny whispered to Leonard.

"No, just hold the phone up to my ear," Leonard whispered back.

"Hi, Sheldon, it's me. Just wanted to see how you're doing. Give a call when you get a chance."

A few minutes later, Leonard's phone rang. Penny grabbed it, whispered "It's Sheldon," hit answer, and held it up to Leonard's ear.

"Hello?" Leonard said anxiously. Then again, "Hello? Sheldon, is that you? Sheldon, what's going on?"

Leonard looked at Penny, stunned. "He hung up. Didn't say anything. It almost sounded like he was crying."

Penny looked shocked. "Sheldon crying? This is bad. What are we going to do?"

"We'll be back there in an hour. Meanwhile, try to reach Bernadette for Amy, and Howard and Raj for Sheldon."

Penny dialed all three friends, but got voicemail for all. She left more or less identical messages, saying that something was up with Amy and Sheldon, that she and Leonard were worried, that they were on the road but would be back soon, that it would be good if somebody checked on them.

Leonard looked over at Penny. Penny looked back, a little startled. "What is it?"

"Well…you may not want to hear this," he said, "but you're an amazing friend, and to somebody that a lot of people find, well, different. It's one reason I love you so much. Sorry, not good timing, but true."

"Okay, okay, that's enough," Penny snorted, but not without a hint of affection. "Look at you and Sheldon – after the way he treats you, you're still there for him."

They were both quiet for a few minutes. Finally Leonard broke the awkward silence again.

"I hope you know how sorry I am, and how much you mean to me," he said softly. "I know I keep making a mess of things, but I'd do anything to make you happy."

"Well, staying away from drunken floozies in the North Sea would be a good start," Penny said with a snarl. "Look, I know you care for me. I just need some time to process all this. After all, you went two years keeping a pretty serious secret from me. That's hard to deal with." She could feel herself getting angrier as she spoke.

"I don't think I want to talk about it anymore right now," she finished, "it's getting me upset. Let's just focus on Amy and Sheldon."

"Okay," Leonard said with another sigh, and drove on.