Sofia and Amber have filled up their diaries, so when Aunt Tilly comes over, she gives them new ones. Hildegard and Clio each have new diaries too. The three girls have plenty to write in their diaries, but they still can't resist sneaking a peek in Sofia's diary. When Sofia isn't looking, Amber, Hildegard, and Clio take her diary to Amber's room to avoid getting caught. But what happens when Sofia realizes that her diary is gone?