In the second installment, In the Deep Blue Sea, Jack, his genius siblings Ava and Matt, and inventor Dr. Hank Witherspoon travel to the Hawaiian island home of Ashley Hawking, a technology billionaire. Hawking and engineer Rosa Morris have built a revolutionary electricity plant that harvests energy from the deep ocean, but someone has been sabotaging the project.
 
In their search for the culprit, Jack and crew navigate an unusual world of characters and suspects, including Hawking and her obnoxiously intelligent son, Steven; a family of surfers who accuse the billionaire of trespassing on sacred land; an ex-Navy SEAL with a fondness for cat photos; and a cigar-chomping man who calls himself the Air-Conditioning King of Hawaii.
 
Readers will learn about the mysteries of the deep ocean, the scientific process, and the potential of green energy as Jack and his brilliant siblings use all their brainpower to survive. Integrating real science facts with humor and suspense and featuring a multiethnic cast of boy and girl characters, this engaging series is an irresistible combination for middle-grade readers.