Heartbreaker escorted Free n' Clear to the front door of her bungalow in my Equestria dreamscape. Opening it she looked down at the filly.
"Alright mate. Ya should get along now before ya parents start wondering where ya are." She lowered her head and looked the filly. Her eyes peered out from the deep shadows cast by the brim of her bowler hat. "And remember mate. Ya have sworn that oath! So don't ya think about breaking it. This ain't some trivial thing! Not a peep about what happened here today. Got it?"
The pale pink filly looked the mare in the eyes and nodded her head. "Right. Got it." Then she picked the basket she'd brought the cookies in and heading off into the late afternoon sun.
The Scale Bearer watched the filly trot away then she closed the door and sauntered into kitchen and retrieved 2 bottles of beer from the ice box. Carrying them in her mouth the earth pony wandered into the living room. Celestia was resting again on the cushions and looking out windows at garden beyond while brushing her mane absentmindedly.
Heartbreaker plopped down next to the alicorn and proceeded open both the bottles and passed one of the lagers to the alicorn. Then she pulled a cigar case from her vest and extracted a cigar. She bit the end of it off and spat into a nearby potted plant. Wedging a match in one of her front horseshoes she scraped it against the bisque ware pot causing it to burst into flames. She then lit the cigar. With that accomplished she leaned back and snuggled into the alicorn's coat. For several seconds no pony said nothing; then Scale Bearer spoke up.
"That was quite a light show ya put on there governor!"
The alicorn smiled and levitated the bottle up to her lips and took a sip. "Well after a thousand years I've learned a trick or two."
The earth pony took a long pull on her cigar followed by a deep swig of her beer. "Do you think that worked? That she believed all of those fireworks you set off were actually part of some great, ancient, arcane oath?"
The princess had resumed brushing mane. "It worked on you when I had you swear your oath years ago. You believed it didn't you?"
The earth pony tapped the ash of her cigar into the potted plant and took an even bigger pull from her bottle of beer. She stared at the label and was silent for awhile. Finally she spoke.
"Yeah. Yeah, I believed it." She looked up alicorn. "However, ya did notice that in spite of yer light show she still had enough wits to ask you a few questions. She may look dainty, but the lights are on upstairs and she's got a spine."
Celestia paused her ongoing mane brushing and looked down at the mare. "Yes. Yes I did. That makes me even more intrigued to see what her true potential is."
Heartbreaker took another pull on her cigar. "So are ya seriously thinking about recruiting her to be a future Mare-in-Waiting?"
"Maybe." The alicorn paused to remove some loose hair from the brush. "I'll have a more detailed dossier worked up for her over the next couple of months. After that I'll see if she keeps her word. If nothing else if she continues to keep her grades up, and stays out of serious trouble, she could end up as a candidate for the School of Gifted Unicorns."
Heartbreaker tapped the ash of her cigar into the potted plant. "Do you want me to continue instructing her? Ya do realize I won't be stay here in Neighpoles forever? Unless yer planning to demote me to foal-sitter?"
Celestia giggled. "Oh Heartbreaker don't worry! If it becomes necessary I'll have another operative assigned to be her handler, and at some point we'll have to start making overtures to her parents." She leaned down and nuzzled the mare. "But I think you're enjoying this which I do find surprising. Pleasantly surprised, but still surprising."
The earth pony silently chewed on her cigar for a bit. "Yeah. I'm just as surprised governor. In many ways she looks like, and comes from, exactly the kind of the place that I despised so much when I was on the street. Pretty, rich, secure in the knowledge that their dear ma and pa would come to the rescue if they fucked up and got caught being naughty!"
A mischievous twinkle dance in Celestia's eyes. "I seemed to remember you said something like that to me. After you succeeded in picking my pocket. You weren't much older that her when you did it."
Heartbreaker snorted and took another swig of her beer. "I'd hardly say I succeeded since ya figgered it out that was me whodunit and ya tracked me down later…" She paused. "Kind of like what I did with Free n' Clear."
Celestia chuckled. "Dear don't forget you succeeded in getting close to me at a formal ceremony, and with over a dozen of my Royal Guard, and another dozen and a half other ponies from your orphanage watching you still got that pendant off my neck."
"Do ya still have that crappy piece of pot metal yer Highness?"
The pearl white alicorn extended her wing and gave the Scale Bearer a hug. "Yes dear I still have it. It's more valuable to me than any diamond or ruby; because it helped me find something much more precious. You."
Heartbreaker snuggled deeper into the alicorn's embrace. Finally she spoke. "Thank you for finding me."
"Your welcome dear."
Both mares continued sit their and silently drink their beers.

To be continued.