Patrick Jane is heading south of the boarder when The Mentalist returns from its long hiatus on March 9.

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When a dead U.S. attorney is found in Mexico during "Black Helicopters,"

Jane's search for the killer will lead him to a separatist commune. As the FBI's faux psychic tries to determine why the attorney was killed, Jane will also need to figure out how she left her home country unnoticed (see photos above).

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Meanwhile, Wayne Rigsby and Grace Van Pelt have stumbled onto a deadly conspiracy that puts their lives - and those of their former coworkers - on the line. Following the murder of Oscar Ardeiles (David Norona), the husband/wife team will choose to ally with a surprising face from the past. While JJ LaRoche (Pruitt Taylor Vince) was once an enemy, the CBI's old Head of Internal Affairs may now prove invaluable.

Although the looming specter of conspiracy has once again cast its shadow over the series, fans can still expect a little levity, such a Jane getting into a spat with a modern cowboy.

"Happy Holidays! Friday was our last shoot day before the new year; here's a good ol' cowboy who tangles with Jane," Emily Swallow (Kim Fischer) captioned a picture of the Stetson-donning culprit during filming in December (see more behind-the-scenes photos for "Black Helicopters" by clicking here).

The Mentalist airs Sundays at 10 p.m. ET on CBS. Click the video below for a preview of "Black Helicopters."