'Frequency' gets a visit from a 'Supernatural' favorite

The ability to change the past seems pretty appealing right now, so it's a good thing that we have The CW's Frequency to let us live vicariously through the time-altering adventures of Detective Raimy Sullivan (Peyton List) and her father, Frank (Riley Smith).
The Nov. 9 episode, "Deviation," sees the introduction of Karl Pierce — played by Supernatural alum Curtis Armstrong. Karl is an inmate who claims that he, like Raimy, can communicate with someone in a different time period: himself