In chapter 21, when Sir Thomas returns from his estates in Antigua, Fanny asks him about the slave trade but receives no answer. The pregnant silence continues to perplex critics. Claire Tomalin, following the literary critic, Brian Southam, argues that in questioning her uncle about the slave trade, the usually timid Fanny shows that her vision of the trade's immorality is clearer than his. Sheehan believes that "just as Fanny tries to remain a bystander to the production of "Lovers' Vows" but is drawn into the action, we the audience of bystanders are drawn into participation in the drama of "Mansfield Park" ... Our judgement must be our own."