Linda Fairstein, internationally bestselling author of the Alexandra Cooper novels and former Manhattan assistant district attorney for more than two decades, has combined her considerable talent, knowledge, and imagination to begin writing a series for kids between ages 8 and 12. Into the Lion’s Den, the first novel in the series, introduced us to Devlin Quick, an enterprising young sleuth.

In the second book, Digging for Trouble, Devlin and her best friend Katie are in the badlands of Mont...