Dolphin morphs, whale friends, sneaking into places as seagulls and a daring underwater rescue mission that results in saving Ax, the younger brother of the Andalite Prince who gifted the kids with morphing abilities before dying. The stakes are raised again as they not only have another near fatal brush with Visser 3 but learn what Yeerks do to lands they colonise. The sound effects really elevate the audiobook experience. SO MUCH FUN!