The Mentalist will air on Sundays this fall. That's one change to which fans will need to adjust.

But a far more pressing concern for viewers of this CBS drama? The state of Patrick Jane. He appears to plummet toward rock bottom in the following network trailer for tonight's Mentalist Season 4 finale.

"The Crimson Hat" will find Jane in Las Vegas and introduce him to Emmanuelle Chriqui's Lorelei Martins, a cocktail waitress who will become a love interest both on the final and beyond.

Check out the official teaser now and visit TV Fanatic later this evening for a detailed review:

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