As Shameless chugs toward its first season finale, it delivered an episode this week that left our critic wondering: Ian's father is not Frank?!?

That storyline will get picked up on next Sunday, as this Showtime hit airs "Daddyz Girl." Look for Amy Smart to guest star and for Frank to face a crisis when his worker's compensation runs out. We'll also learn Steve's actual job.

Check out the following videos for the official promo and a pair of clips from this all-new half hour of Gallagher nuttiness:

Matt Richenthal is the Editor in Chief of TV Fanatic. Follow him on Twitter and on Google+.