She took on the leading role in the independent drama "Under the Skin" (1997), directed by Carine Adler, where she played Iris, a woman coping with the death of her mother. The movie garnered favorable reviews from writers, with "The Guardian" placing it at number 15 on its list of the Best British Films 1984–2009. Janet Maslin for the "New York Times" remarked that Morton "embodies the role with furious intensity and with a raw yet waifish presence" and James Berardinelli wrote that the actress "forces us to accept Iris as a living, breathing individual". She won the Best Actress accolade at the 1998 Boston Society of Film Critics Awards and was nominated for the BIFA Award for Best Female Performance in a British Independent Film.