This takes place as a sort of alternate ending to episode 2*12 "Unnatural Habits", with all of the usual caveats that I own nothing, and am only borrowing these characters, so wonderfully invented by Kerry Greenwood and developed by the writers of "Miss Fisher's Murder Mysteries".
After being kidnapped, tied-up, and threatened with a rather large gun by the fiancé of Jack's ex-wife, Phryne had had enough. The presence of Aunt Prudence and a "fallen" laundry maid with newborn infant in-tow were pushing her perilously close to the edge. She was too exhausted to even think about pouring herself a whiskey and enjoying NOT being the mother of the mewling infant in her front parlour, and so decided to put herself to sleep early. Then the knock came.
With everyone who could decently call at this time of night already in her home (or in the case of Inspector Robinson, at his ex-wife's home, she presumed) Phryne was curious, and truth be told, more than a little apprehensive, about who could be knocking so late.
She opened the door to find Jack standing, sheepishly, on her doorstep. He came in, wordlessly, hat-in-hand, to explain that he had spent the evening with his ex-wife, consoling her in the light of her father and fiancé's dastardly activities. While curious about the extent of his feelings for his former wife, Phryne would never stoop to inquire, simply assuring Jack she understood that his prior relationship with Rosie was one which still pulled on him. Jack seemed to be on the verge of dissuading her from this viewpoint when Aunt Prudence walked into the hallway, sucking all the air out of the room as she was wont to do. Oh, that woman!
Noting that it was late, and that the baby needed sleep, Aunt Prudence left the two in peace, once again, in the front hallway. Jack took the older woman's hint and moved to leave, opening the front door and, then, pausing. He looked back at Phryne with a question in his eyes and a devious smile playing on his lips.
Perhaps, Phryne thought, perhaps THIS is my reward for making it through today in one piece, baby and all. "Jack", she whispered, in a voice both inviting and desperate. For him, that was all it took, as he slammed the door shut (loudly enough for Prudence to hear) and confidently strode to Phryne. Jack grabbed her around the waist with one arm and the face with the other, kissing her greedily as they came up against a wall in the hallway. Silence was a virtue, with Prudence and the baby in the other room and the rest of her household in their rooms directly above. Silence was not a challenge however, as speaking was the last thing on the minds of the couple playing out almost two years of pent-up sexual energy in Phryne's front hallway.
Jack was the first one to pull away from their embrace, leaving Phryne suddenly chilled from the withdrawal of his marked body heat. As she opened her eyes to see the conflicted emotions reflected in his, Phryne realized that she would have to act fast. Any hesitation on her part would give leave for his fear of intimacy, fear of heartbreak, fear of HER to take control of his limbs and march him straight out the door. "Jack, dear", she whispered, "please stay. We should talk about this. But, perhaps, in a less exposed location?" carefully moderating her tones as one would to avoid scaring a small animal.
He opened his mouth, unsure of what would issue forth, only to be interrupted by Aunt Prudence's voice calling from the front parlour "Phryne, have you gone up yet?" and when there was no response, "Well, I guess it's up to me to turn out the lights and lock-up the house. Why on earth does she have a butler and a companion when she still answers her own door to strange, well, not exactly strange, but certainly odd, men late at night and...Oh, you're asleep now, aren't you?" in lower tones meant for the ears of a settling infant.
It had taken every bit of restraint in both Phryne and Jack not to laugh out loud at her Aunt's insistence that Jack was "odd", which had broken the tension considerably. A glance at Jack's mirthful eyes told Phryne that his fear had been momentarily forgotten, giving her the opening she needed to grab his hand and pull him towards the stairs. Jack had no time to talk himself out of removing to her boudoir, only grabbing his hat off of the floor where it had been dropped in the heat of the moment, and stealthily following Phryne up the stairs as Prudence came around the corner, shutting off lights and grumpily doing what she considered to be Mr. Butler's job.
The upstairs hallway was in shadows, and as they quietly moved down in it, hand in hand, Jack's reluctance came back in force. Phryne was barely able to shut the bedroom door behind them before Jack began pacing, worrying his hat in his hands as his mental struggle with the situation appeared on his face. Unnoticed in his inwardly-focused examination, Phryne slowly approached him, placing her hands on his, quieting his ministrations to the hat. She could feel him calm down as they stood, not too closely, but companionably, in her boudoir and felt the realization of this moment, this place, this new coupling, wash over them. When Jack's heartbeat had slowed enough to allow him to think lucidly again, he raised his head and asked, simply, "What now"?
Phryne was momentarily taken aback with the honest, open, and unassuming expression in his eyes which echoed in his voice. Her own machinations, so intent on getting him here and assuring his pliability, no longer seemed honorable. In a subdued tone which he had never expected to come out of this brash, confident woman, Jack was strangely comforted to hear "I don't know, Jack. I don't know what's next."