The IRT has to call in the big guns in Wednesday's Criminal Minds: Beyond Borders. In this exclusive sneak peek, Prentiss (Paget Brewster) joins the team to help out on a particularly tricky case.

When an American goes on a murder spree in Taipei, it soon becomes clear there may be a connection to an old BAU case: the Vinegar Hill Slayer. At the time of the original Brooklyn murders, both Prentiss and Clara (Alana de la Garza) were working as interns at the U.N. And as Clara reveals, these murders hit particularly close to home for them since they were friends with one of the victims, a translator at the U.N.

But before the BAU could fully investigate the original murders, 9/11 happened and the team had to shift its focus to terrorism. Now, 16 years later, it appears the Vinegar Hill Slayer has resurfaced abroad, and Prentiss and Clara are going to do everything they can to get justice for their friend.

Criminal Minds: Beyond Borders airs Wednesday at 10/9c on CBS.

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