It had been by chance that she'd glanced through the window as she and Stew raced down the hallway. Penelope's attention had been on the pipes and light fixtures that threatened to trip her, not the sunbeams shimmering through the ocean surface. Maybe it was the glint of artificial lighting or a faint sound of something hitting the surface - and later she would let herself believe it was an emotional connection - but she turned. Just a shift of sapphire towards blue and she saw it.
The yellow sub had been a sight all on her own, Penelope's fist connecting with the window before Stew could even ask what was going on. Their comms were down, they had to hear her, just keep knocking.
The moment Four turned and her light began searching the hull of the upturned ship, Penelope knew her spontaneous plan had worked. She hadn't anticipated who would be at the helm, however, her knuckles stuttering for only a beat as she saw his face. He hadn't seen her yet, the anxious searching evident on his usually cheerful face. It was only a moment, but it burned into her mind… he was worried about her. Penelope's typical reaction would be to brush it off. Parker did enough fretting for a lifetime. She could manage well enough on her own and had been for much of the day.
And then, he saw her. Her Gordon, who exuded every ray of sunshine. No longer broken. Not putting on a show for the room to see. Just him and as their eyes met and her hand stopped the incessant beating against the glass, Penelope smiled with him. A warmth, unexpected, but not unwelcome, spread through her chest at the sight of him and in that moment, she knew everything would be alright.