The backstage of the Paris venue was unusually quiet for once-just the hum of a vending machine and the distant bass of the show's final soundchecks reverberating through the walls. Mars sat cross-legged on the couch, headphones covering her ears as she tinkered with a new melody on her laptop. A notebook sat open beside her, filled with scribbled lyrics and chord progressions, arrows pointing to rearranged phrases, and little stars marking the lines she liked best. Her fingers drummed idly on the trackpad as she played back a rough cut of the song she was working on, titled Eyes.

The album she'd been chipping away at was a secret-a collection of songs that started taking shape shortly after she and Billie became serious. Every verse, every chorus, every note was a reflection of their relationship-messy, intoxicating, and sweet all at once. Mars had never been one to pour herself out so nakedly in her music, but loving Billie felt different. This project wasn't about commercial hits or topping charts; it was a personal love letter.

She barely noticed when the door to the green room creaked open.

"Well, well, if it isn't the other O'Connell sibling," Mars said with a grin, pulling off her headphones as Finneas stepped inside.

Finneas gave a mock scowl. "Sometimes I think you forget you were my friend before you even knew Billie existed."

Mars snorted, closing her laptop. "True, but your sister is hotter, so..."

Finneas clutched his heart dramatically. "Ouch. Betrayed."

"Sorry, Finch," Mars said, tossing him a water bottle from the mini-fridge. "But you'll survive."

"Barely," Finneas muttered, cracking open the bottle and taking a sip. He leaned forward, elbows on his knees, as he gestured toward her laptop. "So... romance, huh?"

Mars nodded, her expression softening. "Yeah. It's my love letter to Billie. She doesn't know about it yet."

Finneas raised an eyebrow, intrigued. "Wait-you're working on a whole album for her and didn't tell her? Bold."

Mars shrugged, running a hand through her short curls. "It's not really for the public, y'know? It's more for her. But... if it ends up out there, well, I won't complain."

Finneas smirked. "She's gonna freak. In the best way."

Mars leaned back, exhaling as she drummed her fingers on the water bottle. "That's the plan. But right now, between parenting and touring, finding time to finish it has been brutal."

"Speaking of parenting," Finneas said, "where's Z?"

Mars smiled at the mention of her son. "He's with Janice for a bit, probably terrorizing the tour bus with his toys."

"You really took him on tour with you?" Finneas asked, his voice a mix of admiration and disbelief. "How's that been?"

Mars let out a weary laugh. "It's been... a lot. The amount of planes we've caught? Horrendous. Half the time, I forget what city we're even in. And forget sleep-I'm running on fumes. But I wouldn't trade it for anything. Zaine needs me right now."

Finneas gave her a thoughtful look. "That's gotta be tough. Balancing everything."

"It is." Mars ran a hand down her face, exhaustion creeping in. "But we make it work. He's been through too much to be left behind."

Finneas nodded, understanding. "He's lucky to have you."

Mars's expression softened. "Nah. I'm the lucky one."

They fell into a comfortable silence for a moment before Mars shifted the conversation back to music. "So, you're the producer guru. What do you think of this?" She leaned over, opening her laptop and playing him the rough cut of Eyes.

Finneas listened intently, nodding along as the soulful chords and Mars's smooth, heartfelt voice filled the room. When the track faded out, he gave an approving smile. "It's perfect. It's you."

Mars grinned, relieved. "Think she'll cry?"

"Oh, for sure," Finneas said with a laugh. "Billie is going to love this."

Mars chuckled, closing her laptop again. "Good. That's all I care about."

Their conversation drifted to lighter topics-Finneas's own projects, funny tour stories, and life on the road. But before long, Mars's phone buzzed with a text from Janice.

"Z's asking for you. He's not happy."

Mars sighed, already anticipating the bedtime chaos awaiting her. "Duty calls," she muttered, standing and grabbing her hoodie.

Finneas clapped her on the back. "Good luck, Dad."

Mars smirked. "Thanks, Uncle Finch. See you later."

She made her way back to the tour bus, already bracing herself for whatever mood Zaine was in. When she stepped inside, she found him curled up in a blanket on the couch, pouting dramatically. Rexy, his stuffed dinosaur, sat beside him, looking equally displeased.

"Hey, Z bear," Mars said softly, crouching down to his level. "What's up, kiddo?"

Zaine crossed his arms over his chest, a frown etched deep on his little face. "I don't like it here."

Mars's heart ached at the frustration in his voice. "I know, ursinho. It's been a long trip, huh?"

Zaine nodded solemnly. "I miss home. I miss Billie."

Mars scooped him into her arms, holding him close. "I know, baby. We'll be home soon, I promise."

Zaine sniffled, clinging to her. "I want dino nuggets and Billie hugs."

Mars kissed the top of his head, her heart full of love and guilt. "Me too, Z. Me too."

She rocked him gently until his breathing slowed, and the tension melted from his small frame. It wasn't easy-being a parent on the road, juggling her career and Zaine's needs-but moments like this made it all worth it.

Mars sat with him in her arms for a long time, the steady rhythm of his breathing grounding her.