SHIRLEY SCHMIDT BEGINS AN AFFAIR WITH HER EX-HUSBAND, IVAN TIGGS, BELIEVING HE HAS LEFT HIS WIFE, AND ALAN SHORE AGREES TO BE CO-COUNSEL ON AN ATTEMPTED MURDER CASE WITH THE MAN WHO HELD A CAKE KNIFE TO SCHMIDT�S THROAT, ON ABC�S �BOSTON LEGAL�

Tom Selleck Guest Stars as Ivan Tiggs

�Ivan the Incorrigible� � Shirley Schmidt begins an affair with her ex-husband, Ivan Tiggs (Tom Selleck), believing that he has left his new wife, Missy (Meredith Patterson). Then Missy -- who is still with Ivan -- suspects her husband is cheating on her and asks for Schmidt�s help. Meanwhile, Alan Shore agrees to be co-counsel on an attempted murder case with Jerry Espenson (Christian Clemenson), who has been in therapy since holding a cake knife to Schmidt�s throat, on �Boston Legal,� TUESDAY, APRIL 18 (10:00-11:00 p.m., ET), on the ABC Television Network.

Boston Legal� stars James Spader as Alan Shore, Julie Bowen as Denise Bauer, Mark Valley as Brad Chase, Rene Auberjonois as Paul Lewiston, with Candice Bergen as Shirley Schmidt and William Shatner as Denny Crane.

Guest starring are Tom Selleck as Ivan Tiggs, Adam Arkin as A.D.A. Douglas Kupfer, Meredith Patterson as Missy, Christian Clemenson as Jerry Espenson, Allan Louis as Ande Mkeba, Howard Hessman as Judge Robert Thompson, Lauren Stamile as Audrey, Michael Raymond-James as Kevin Armus and Takayo Fischer as court clerk.

Ivan the Incorrigible� was written by Phoef Sutton & Andrew Kreisberg and directed by Bob Yannetti.

��Boston Legal� is broadcast in 720 Progressive (720P), ABC�s selected HDTV format, with 5.1-channel surround sound and Spanish subtitles via secondary closed captioning.

A TV parental guideline will be posted closer to airdate.