Forget unwanted pregnancies and STDs. Who knew the consequences of teenage sex could be so lethal?

On this Thursday's new episode of The Secret Circle, as previewed by Executive Producer Andrew Miller in the following video, we'll learn more about the curse cast upon the Blakes and the Conants by some old witch. Let's just say new couple might soon be regretting its night of "mad, passionate" lovemaking, as Miller puts it.

What else can fans expect from the aptly-titled "Curse?" Watch the promo and a sneak peek from it now:

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