Ewan McGregor and Helena Bonham Carter lead an impressive cast in this magical tale – but its focus on two unlikable young protagonists proves wearing Ewan McGregor and Helena Bonham Carter lead an impressive cast in this magical tale – but its focus on two unlikable young protagonists proves wearing H ere is a lacklustre kids’ animation with an ostensibly starry voice cast including Ewan McGregor, Helena Bonham Carter , Mel Brooks and the late Terry Jones. (Oddly, David Walliams is announced