The Guest lead for the episode is Ray Haffner, a no-nonsense alpha male who is a CBI Supervising Agent and a man who runs a very tight ship.

 

Mainly about Owain meeting Prince William and Kate, but includes a little info about The Mentalist

 

Excerpt:

The Mentalist cast has just received their first script of the new season, which involves the aftermath of the shocking reveal of Red John (Bradley Whitford), as well as Patrick Jane's (Simon Baker) attempts to extricate himself from the law. "But we all suspect this is not the last we'll see of Red John," Owain adds. Though Bradley's character was killed, Owain reminds us that a Season Two episode hinted that Red John may be more than one person. "On the wall of a bathroom in Mexico in blood was written, 'He is man,' which is believed to be short for 'He is many.' Red John may be a whole network of people, so Bradley may not have been the guy. Red John is a series-long cliffhanger for us, so who knows? Maybe Prince William will turn out to be Red John!"

Confirmed by the ever helpful Karl Sonnenberg