Nearly a month into production, "Romeo + Juliet" star Claire Danes has taken over the costarring role opposite Arnold Schwarzenegger in "Terminator 3: Rise of the Machines," replacing newcomer Sophia Bush, reports Variety. Danes, 23, reported for work Monday, says the trade paper. She will play the love interest of "Terminator" vet John Conner (Nick Stahl), now in his 20s. The sci-fi film's director, Jonathan Mostow, said Bush, age unreported, who recently costarred in "National Lampoon's Van Wilder," came across as too young for the part. "This was a difficult decision because Sophia is a talented and charismatic performer," Mostow told Variety. "However, we feel, after reviewing the dailies, that her appearance and manner play younger than what we wanted for the role." The paper points out that the pressure is on for the success of the latest installment in the cyborg series, scheduled for release in the summer of 2003, since its budget is at least $155 million. In addition, Mostow, who has only five other films to his credit (starting with 1989's "Beverly Hills Bodysnatchers"), is stepping into the director's chair that was previously occupied on the "Terminator" movies by James Cameron.