One day at Santa Monica beach, a young girl and her father came to hang out. "Have fun swimming, Mabel," said the father. "I'll be right over here if you need me." Mabel gave her dad a thumbs up as she ran toward the ocean when suddenly, she saw a young boy around 11 years old like her, but he went back underwater. Mabel got closer to a nearby dock where the boy was. "Hello?" She called out. "Hey." The boy said from behind her. Mabel jumped in fear. "Oh my gosh you scared me." She said. "Sorry about that, my name's Dipper." He apologized. "I'm Mabel." She replied. "I was actually wondering if you wanted to go on a walk on the beach, since you looked lonely." "Oh, that's very nice of you, but I can't, my mom is gonna be worried if I don't get home soon." Dipper said. "Plus, I'm not a big fan of going on walks." "That's okay, maybe tomorrow we can hang out!" Mabel exclaimed. "If you want to meet me by my house, I live by the ocean just over there." "Sure." Dipper replied as Mabel ran to her father and Dipper dove underwater with the flick of his tail after she was out of sight. "Dad, I made a new friend, is it okay if he comes over tomorrow?" Mabel asked. "As long as you're not crushing on this boy, I don't see why not." Her father replied. "I don't think you have to worry about that for a while." She said as they drove home.

When they got home, Mabel's dad was looking for something in his bedroom drawer, a special gift for Mabel's birthday. He came across a small gift box with a note that said, For Mabel's 12th birthday. "Hi dad." She greeted her father as she walked into his room. "Hey kiddo." He replied. "Come sit on the bed." He gave his daughter the box. "What is this?" She asked. "Your mother wanted you to have this on your 12th birthday since the day you were born." He replied. Mabel opened the box and inside was a necklace made from an actual peridot. "It's my birthstone, thank you dad!" She cheered. "You're welcome sweetie." He said as he kissed his daughter and sent her to bed. "Goodnight." "Goodnight Dad." Mabel replied.

The next morning, Mabel ran down to the dock in her backyard, looking for Dipper. He popped his head up from the water. "Mabel, over here!" He shouted. "Hey Dipper." She replied. He had some worries showing on his face. "Listen, if I we're going to be friends, then I need to show you who I really am." He said. "You don't need to show me anything, I think you're perfect the way you are!" Mabel complimented right as Dipper climbed on the dock, showing his shimmering blue tail to her. "Wow, I was not expecting that." She said in shock. "Wait, you're not scared?" He asked. "That was my big reveal." "I'm not scared, just shocked, but now there's nothing that can stop us from being friends." Mabel says as she hugs the young merman. "Thanks Mabel, you know, I'm actually near the surface more than underwater, as far as I know, I'm the only merperson that has so much knowledge about the land above, that's also the reason I don't have many friends in the sea." Dipper explained. "You've never had a friend before?" Mabel asked. "I actually have one, her name is Gail, her fin was caught in the remains of a shipwreck, but I saved her." He said. Mabel looked down at his arm to see a bracelet with a peridot charm on it. "Have you always had that bracelet?" She asked. "No actually, my mother gave it to me, she said my father wanted me to have it as soon as I turned 12." Dipper replied. "Weird, I got this necklace last night from my dad, and he said my mom always wanted me to have it on my 12th birthday." Mabel explained. "Wait, your charm is a peridot like mine, when's your birthday?" "August 31st." He replied. "No way, mine too!" She exclaimed. "That is so cool!" Dipper said. They kept talking about themselves to get to know each other. "My mom is the queen of the sea, and my Uncle Gilbert is her head advisor." Dipper explained. "What about your mom?" "Well, she died in a car accident with my twin brother, Mason." Mabel said with tears forming in her eyes. "But she was the most beautiful woman." "But, didn't she pass when you were little?" He asked. "I think it happened around a year ago when I was snooping around for Christmas presents when I found a photo of my parents, Mason, and I." She replied. "What about your dad, what's he like?" "My dad was killed in a shark attack as well as my twin sister." Dipper said. "I don't remember her name though." "Oh." Mabel said, hugging her new friend. "You know, you are pretty cool Mabel, but I kinda wish I could meet your dad, he seems like a nice guy." Dipper said. Mabel puts her hand on his when suddenly, Dipper's blue tail magically changed into a pair of human legs. "What's going on?" He asked. "I don't know?" Mabel replied as Dipper was changed into an orange tee and blue vest, a pair of shorts and slip on shoes. "I have legs." Dipper said very quietly. "Human legs." "Have you always been able to do that?" Mabel asked. "Never." Dipper nodded. "I guess now I can see your dad!" "Here, I'll help you walk until you have the strength to do it by yourself." Mabel said as she grabbed his arms and took small steps like she was teaching a baby to walk. "Just take it one step at a time and try not to lose your balance." "Wait, let go," Dipper said. "I think I'm getting the hang of this!" Mabel lets go of his arms as he walked like a normal human being. "I don't want my dad to find out you are a merman, so just pretend like you were born on dry land." She demanded. Dipper nodded as the kids walked toward the house.

The kids went into the house where Mabel's father was reading his newspaper. "Hi, Dad, this is Dipper, the boy I met at the beach yesterday." She introduced. "Patrick Pines, nice to make your acquaintance, Dipper." Dipper shook Patrick's hand. "Make yourself at home." Dipper smiled. "C'mon, let's go to my bedroom." Mabel said as she and Dipper ran upstairs to her room. "So this is where you sleep?" Dipper asked. "Yup, I like to bounce on my bed." She replied. "You can look around my room if you want." Dipper looked around the room and saw a lot of sweaters and stuffed animals, but what really caught his eyes was Mabel's pictures and posters. "Who are these guys, Mabel?" He asked. "Sev'ral Times, my favorite boy band." Mabel answered as she grabbed her iPod and a pair of headphones. She put the headphones on Dipper's head and played a song from Sev'ral Times. Dipper was disgusted by the music and he threw the headphones on the floor. "Sorry, I don't like their music, it's just weird." Dipper said as he continued to look at photos. He found a Polaroid photo of Patrick, a woman, and two babies. Dipper gasped at the sight of the woman in the photo. "What's wrong?" Mabel asked as Dipper picked up the photo off the floor, showing it to her. "Mabel," he said in shock. "That's my mother."