Played Ted Danson's son and Jack Lemmon's grandson in "Dad," a film based on a William Wharton novel
Visited the Steppenwolf Theater in Chicago during a cross-country drive with playwright-actor Jonathan Marc Sherman and actor Josh Hamilton; inspired to start a theater group
Started a reading series in NYC with Sherman and Hamilton
Played a reluctant platoon leader in "A Midnight Clear"; also featured Steppenwolf's co-founder Gary Sinise and friend Frank Whaley; second film based on a Wharton novel
Wrote, directed and edited the short film "Straight to One"
Acted in Jonathan Marc Sherman's "Sophistry" at NYC's Playwrights Horizon
Acted in the Steppenwolf Theater Company production of Sam Shepard's "Buried Child" in Chicago; project reunited him with Sinise who directed
Portrayed the Pip-like Finn in the contemporary remake of Dickens' "Great Expectations"
Appeared as Jess Newton, the charming drunken brother in Linklater's "The Newton Boys"
Cast in small role as a concerned guidance counselor in Frank Whaley's feature directorial debut "Joe the King"
Acted in Williamstown Theatre Festival staging of Tennessee Williams' "Camino Real"
Starred as Michael Almereyda's slacker "Hamlet"; Zahn played Rosencrantz
Again collaborated with Linklater on the digitally-shot "Tape," co-starring Robert Sean Leonard and Uma Thurman
Re-teamed with Whaley in "The Jimmy Show"; written and directed by Whaley
Guest starred on the ABC series "Alias" as a captured CIA agent whose allegiances may have shifted
Portrayed an Interpol agent, chasing an arms dealer (Nicolas Cage) in Andrew Niccol's "Lord of War"
Cast as part of an ensemble in Linklater's "Fast Food Nation"
Cast in "The Coast of Utopia," playing Mikhail Bakunin; received a Tony Award nomination
Acted with Mark Ruffalo in the crime drama "What Doesn't Kill You"
Cast as Edward Dalton, a vampire researcher in the sci-fi film "Daybreakers"
Re-teamed with Antoine Fuqua for "Brooklyn's Finest"
Co-starred with Kristin Scott Thomas in Parisian-set thriller "The Woman in the Fifth"
Starred in found-footage thriller "Sinister"
Featured in the horror hit "The Purge"
Co-starred in the western remake "The Magnificent Seven"
Co-starred with Amanda Seyfried in Paul Schrader drama "First Reformed"