Peter Jacobson portrays Wally Jabrowski, an eccentric loner who possesses the Bus Ticket, which immediately transports anyone who touches it — or who is touched with it — to Gallup, N.M. Wally knows more about the lore and history of Room 10 than he chooses to let on, and he is reluctantly recruited by Joe to help him unravel its mysteries.

While perhaps best known for his recurring role as the cunning defense attorney Randy Dworkin on the long-running hit show Law & Order, Jacobson's C.V. boasts an eclectic mix of TV, film and stage work.

His most recent film roles include the action-thriller Domino, with Keira Knightley; Failure to Launch; Good Night and Good Luck, which received a SAG Award nomination for outstanding ensemble cast; and the upcoming Dreamworks/Paramount film Transformers, directed by Michael Bay.

Jacobson's television work includes the HBO films Path to War and 61*, directed by Billy Crystal. He also has guest-starred on such series as CSI: Miami, Will & Grace, Criminal Minds, Scrubs and ER. He is currently in Australia filming the USA Networks six-hour miniseries The Starter Wife, opposite Debra Messing.

He has also spent many years doing theater in New York, where he appeared in a wide variety of plays, such as Taming of the Shrew and the Public Theatre's Shakespeare in the Park presentation of Comedy of Errors; Waiting for Lefty, directed by Joanne Woodward; David Mamet's The Water Engine, at the Atlantic Theatre Company; and the original New York production of Steve Martin's Picasso at the Lapin Agile.

A Native of Chicago and a Brown University graduate, Jacobson later attended the prestigious Juilliard School.