FBI 3x15 "Straight Flush" Season 3 Episode 15 Promo (Season Finale) - When five prominent men are killed at a trendy New York City restaurant, the team's investigation brings them into contact with a lieutenant in Antonio Vargas' cartel, triggering a long-awaited showdown between Isobel and Vargas. David Zayas returns as Vargas, on the third season finale of FBI, Tuesday, May 25th on CBS.