'Pretty Little Liars' books Missy Franklin to guest star

Watch out, "Pretty Little Liars" -- an Olympic gold-medal winning swimmer is about to turn up in Rosewood.

ABC Family just announced that Missy Franklin, the high school swimmer who recently won four gold medals and a bronze at the 2012 Summer Olympics in London, will be guest-starring on an episode of "PLL" when the show returns for the back half of Season 3.

Franklin will appear as herself, wanting to meet with Emily (Shay Mitchell) to talk shop about swimming. There are no details as to which episode it will be when the show returns.

But "Pretty Little Liars" returns briefly next week for the annual Halloween episode. This one is called "This is a Dark Ride"and airs Tuesday, Oct. 23 at 8 p.m. ET/PT on ABC Family.