This novel in verse alternates between the voices of two sisters, 11-year-old Claire and 13-year-old Abigail, with occasional contributions in the voice of the lake where they are spending the summer with their dad and pregnant stepmother. Abigail (who now asks to be called “Abi”) is diving into adolescence, and is struggling between her feelings for two boys: TJ, a longtime summer friend whom she kissed at the end of the previous summer, and Brock, this year’s hot new guy. Claire is wary of the new Abi, and resents being asked to cover for her when Abi breaks their father’s rules. Claire also misses the way things were when it was just the three of them, before Pam, her stepmother, came into the picture. The pending arrival of a baby brother is yet another transition in the family structure. Frost’s deft skill with poetic form (including quatrains, kayak poems, free-verse, and acrostics) keeps the focus on the relationship between the sisters, as well as providing insight into the thoughts they keep private. Although their history includes a tragedy—their mother was struck and killed by lightning many years earlier—this is a summer without melodrama, but rife with the usual challenges of adolescence, family, friends, and change. (Ages 10-13)