Fringe, Season 1

[Walter is singing 'Dashing Through the Snow', Olivia walks in]

Olivia:
Hey, what the hell's he doing?

Astrid:
He thinks it will help him remember where he's heard about the red and green lights.

Olivia:
Okay.

Peter:
We've got good news. We think we understand how it was that Ben was abducted. Those red and green flashing lights? They put the father into a hypnogogic state.

Olivia:
And we think we might've I.D.ed the woman responsible.

Walter:
I have it! Christmas, Christmas leading to Christmas carols, one of which is 'Jingle Bells' which lead naturally to 'Dashing Through the Snow', which of course, inevitably leads one to Dash.

Astrid:
To dash?

Walter:
Dashel Kim... the man who mentioned the lights to me. I'm sure of it.

Olivia:
Where is he, Walter? Can we talk to him?

Walter:
Well, I guess that would depend on whether he has succeeded in killing himself or not.