As an enthusiast of both paleontology and ichthyology the MEG series has been a staple of my literary diet. The first book established a mythos that I adored, the second remains one of my all-time favorite novels, and the third is quite plainly a fun read of non-stop excitement.
For the sake of candor, I should admit that since having read the third book and the preview for Hell's Aquarium online, I have been apprehensive regarding this book and specifically the newest terrifying denizen of the deep in the MEG series - the Liopleurodon. In point of fact, I think the only reason that I didn't enjoy the third book as much was because I couldn't get around the fact that there was supposedly a predator existing in the depths of the Philippine sea in excess of 120 feet! Immediately a nagging voice was unearthed in the back of my mind, screaming, "There is no such creature known to exist!" Following that, the online free preview both tantalized me with Steve's writing style and the characters that I have come to adore, and caused me to be still more unnerved, discovering the 120-foot monster to be a Liopleurodon with a skull in excess of 30 feet! I became confused instantaneously; the series with such an eye to attracting fans of prehistoric aquatic fauna is featuring a grossly paleontologically inaccurate specimen, hyping the Liopleurodon to more than twice the size of what we know for even the largest specimen of this pliosaur? However, with tens of millions of years for this animal to evolve if left undisturbed in a subterranean sea, who is to say that its size couldn't increase? I remained hopeful that Steve would provide an explanation... and provide he did! My one fear and quibble for the book laid to rest in an evolutionarily plausible fashion, I may now go back and reread Primal Waters so that I can fully appreciate that book without being concerned with an inaccurate leviathan of ludicrous proportions!
With "the bad" (if the above worry could even have been considered as much) out of the way, I should move on to the good... which literally is the ENTIRE book. Hell's Aquarium is the singularly most enthralling novel I have read since The Trench, steering the series into uncharted waters of infinite possibility. Angel is back in all her rapacious, cantankerous glory, but the creatures I found myself yearning to read about just as much as Angel were her offspring, particularly her larger two female pups, Belle and Lizzy, referred to by the Tanaka Institute staff as "the sisters". What's compelling about the sisters is that we see them not only as Megalodons but as animals with distinct personalities which make them memorable and enticing for the reader. Long have we seen Megalodons as fiercely territorial and solitary; now we see the sisters in a symbiotic predatory relationship. Belle is the brawn to Lizzy's brain. Lizzy appears strategic and calculating in attacks, while Belle is pure, unbridled primal fury.
All of the main characters are back, with David now 20 years old and donning the mantle of main protagonist (Jonas coming in at a close second). This book seems to groom David as the Taylor we'll be following most closely in future books as Jonas advances in years and becomes less capable of taking on these apex predators and coming out unscathed. A glut of new and memorable characters are present, including bi-polar Monty whom David befriends on his trip to Dubai, their relationship echoing that between Jonas and Mac. From the Monterey bay to Dubai, this book ceaselessly churns out intrigue and action in a manner that fans of the series will swarm about as if it were chum!