For most of his life, Rick Castle had been surrounded by women. He really didn't mind, because the women in his life were strong, capable, and amazing. From his mother to his daughters to his wife, he loved them.

But when he found out that he was going to be a father to twin boys, he couldn't help himself. He walked around – well, Kate said he strutted – with his chest puffed out. He was a man, doing manly things! He was going to be a father of twin boys! He was great!

It was in private moments that he started to really think about being the father of sons. What did he know about raising sons? Being "famously fatherless" meant he hadn't had those ritual father and son moments. He'd never had a dad to teach him how to fish, or throw a ball or to shave. (It was one of the weirdest parts of his life that his mom taught him how to shave because as she said, "I do shave parts of my body, Richard." He still got the shivers from those memories.)

So early one morning, when Kate was sleeping, he had a conversation with the boys in her womb. "Okay, Jake and Reece, I need a favor. Please give your old man a break. I don't know much about boy stuff. I was surrounded by theater people in my youth, so I know a lot about hitting your mark, or the lyrics to most musical numbers, but I didn't learn about baseball or playing in mud or stuff like that." What he didn't know was that Kate was awake and had heard every word. Then he felt her hands in his hair, and he heard a little sniff.

"Babe, please don't say that! You're an amazing father. And I'm sure you'll be a fantastic father of sons!" She sat up a little and he moved to be next to her. She still had her hands in his hair, soothing him. "Besides, our daughter loves to play in the mud, and you do a pretty good job when she does," she chuckled a little at his little boy grin. Then she got serious. "Remember what you said to me many times when I was pregnant with Lily and scared to death that I wouldn't be a good mother? You told me I'd be great and that it was a new adventure for us. And that we'd go on the adventure together. And that's what we'll do now – go on an adventure with Jake and Reece and Lily. I can't wait!" She leaned down and kissed his lips softly, and he knew she was right.

And now, years later, he was ready for a new adventure. Kate was going to take Lily out to lunch and a movie and he was going to stay home with two three year olds. They were going to be staying inside – it was rainy and Reece was getting over a cold – but he knew the three of them could entertain themselves without a problem. He couldn't wait to see what the boys would come up with; he always let them lead the way. In the past, that meant the couch became a pirate ship, or they watched him make s'morelettes and then devoured them. They might have a mini Olympics, complete with opening ceremonies. Or it might be as simple as doing puzzles or playing Candy Land or watching movies.

So after a traditional Castle/Beckett Sunday morning brunch, the Castle men kissed and hugged the Castle women on their way out for the day. Then Rick turned to the boys and asked, "So what are we doing today, gentlemen?" He watched as the boys shared a look and a grin, and then they turned to their dad.

Reece, the spokesman for the twins, spoke up. "Daddy, today we want to pretend to be those guys that get to go in space and go to Mars!" Rick smiled to himself. The "Mars 2018" Viggo Jansen project had finally reached Mars recently. The boys had been fascinated with the idea of traveling to Mars ever since Rick and Kate had told them they had wanted to go to Mars themselves, and that they had met Jensen years before.

"Okay, guys. Where's our space ship? And do you think we'll be home by the time Mommy and Lily get home?" Rick couldn't help but grin as his sons started to tell him what they needed to do, and how Jake's newest invention, the "super duper speed button" would get them to Mars and back just in time for dinner with Mommy and Lily. He let them take him by the hand and to their toy chest so they could get out some of the dress-up stuff that Gram had given her grandchildren over the years. They also took their light sabers and a few other toys so they would be prepared.

The three of them had so much fun over the hours that Kate and Lily were gone that they barely even missed them. But when the Castle women got home, the Castle men made the suggestion for some pizza since space food was so boring. They sat down to dinner as a family and discussed their day.

As Rick and Kate tucked three tired kids into bed, Rick thought about how he was so lucky to have all these people in his life. And then he thought about how much he loved these adventures, and he wouldn't trade them in for anything.