William and Melody had just stopped from the world ending. As they walk back to the station she turned to him, "so detective, should be celebrate our victory?"

He looks at her, "thank you, but I have to get to my family, before we miss the comet"

"Of course. Take care. I'm home we meet again in the future"

A few minutes later, after confirming they got all the vials and sent them back to the University, he sends his goodbyes to Pendrick and says good night to the inspector, as he leaves the station.

He begins walking when he sees Julia with Susannah in her arms, as he runs to them, and hug each other

"William…" is all she says and they kiss as Susannah coos, "are you alright?"

He nods, "are you both?"

"Yes."

He caresses both her arm, and Susannah's head, "I'm sorry…I didn't know what to do. She needed at least one parent alive" as he looks at his little girl

Julia caresses his cheek, "don't apologize. I understand."

He grabs her face in his hands, as they kiss, and smile at each other, when they hear people cheering, and thought they were cheering for them, when they looked up and saw the comet.

"Oh, my goodness. It's beautiful" Julia says

William turns to Susannah, "look at that Susannah…" he says as he points to the sky, "that is Halley's Comet. The next time you see that…you will be an old woman"

They both laugh, as Julia says, "and the world will be a very different place."