Fade in background image on start passage

I'm using Sugarcube for Twine 2.0. I'm hoping someone can help me with the following:

I have a background image that is the same on each passage throughout the game, but I'd like it to fade in on the start passage (and only this passage). Is there a way to
a) have a background image fade in
b) have the fade in effect occur on only one passage?

Thanks!