Christopher Plummer tells us about his late castmate on in-progress ''Imaginarium of Doctor Parnassus'' Last week in London, Heath Ledger was busy wrapping up nearly six weeks of long days and nights he'd spent at often-frigid outdoor locations, filming scenes for The Imaginarium of Doctor Parnassus. But with Ledger's death on Tuesday in New York, the movie has become a reported $30 million question mark, since there were additional weeks of studio-soundstage filming yet to be done in Vancouver. Imaginarium is a fantasy tale, co-written and directed by Terry Gilliam, a filmmaker known for his outlandish visual invention (he previously worked with Ledger on 2005's The Brothers Grimm). Christopher Plummer, who's now 78, plays the title character, an eccentric theatrical trouper trapped in a deal with the devil (Tom Waits) that dooms Parnassus's lovely daughter, Valentina (played by British-born model Lily Cole). Ledger was playing Tony, a roguish charlatan who gets mixed up with the troupe and begins a series of through-the-magic-mirror adventures to a strange parallel universe. Early on Sunday, Jan. 20, Plummer boarded a plane back to New York and went on to his Connecticut home. Ledger took a different London-to-New-York flight and repaired to a SoHo apartment where, two days later, he was found dead. EW spoke with Ledger's final costar about what happened, what the filming was like, and what may or may not become of the last scenes Ledger ever performed. More...