Season 4

01 Fruit of the Poisonous Tree (1) Episode 110th November 1990 While Frank is in Washington to talk to Paul about returning to work, Dan calls to say Vinnie missed his last check-in. Frank goes to Vinnie's house and finds evidence that he was kidnapped. Despite Paul's objections, Frank begins his own investigation, finding out from Carlotta that Vinnie was looking into the death of a priest in El Salvador. Frank follows the trail to Miami and Michael Santana, a disbarred Federal prosecutor, and the last person Vinnie contacted. Santana refuses to help Frank, saying he doesn't know anything about Vinnie's disappearance. Digging deeper, Frank stumbles upon a CIA investigation and is ordered to back off. (source: http://www.plasticcow.com/wiseguy) 02 Fruit of the Poisonous Tree (2) Episode 210th November 1990 03 Black Gold Episode 317th November 1990 04 The Gift Episode 424th November 1990 05 La Mina Episode 51st December 1990 06 Witness Protection for the Archangel Lucifer Episode 68th December 1990 07 Point of No Return Episode 78th December 1990 08 Dead Right Episode 815th December 1990 09 Changing Houses Episode 922nd December 1990