I'd say a loose adaptation, with bits from the second book going in (like the billionaire financier plotline - that is from book 2, though that is far more elaborate and creepy in the novel and he is a total villain).
Not a lot of comedy in them, the character Mac is snarky as hell, but Jonas is quite a tortured guy. Books are rather serious, maybe a bit to serious. I'm not in love with either of the leads, both Jonas and Terry are kinda full of themselves. And so many people are so stupid, treating the Megs and other prehistoric creatures like they are garden variety animals. Of course, most of them get eaten in the end. The body count in the books is huge, and some characters live on book to be killed in the next one. Terry and Jonas end up having 2 kids, and books 3 and 4 feature them heavily as well. Book 3 has a great reality tv plot line that could be super fan to do. But y the end of book 1. they have a Meg in captivity, she becomes the world's biggest attraction - which the movie didn't do.
The basic plot is the same, but the details are all wrong. The Institute is Japanese, so is the female lead and her father, Jonas was first a navy submarine pilot who on a deep dive thought he saw a Megalodon and panicked and kill two crew members due to the compression of surfeasing to fast. He became an expert in Megalodons, giving lectures on them and his theory that they aren't extinct - everyone thinks he is crazy - Ancient Aliens style. He gets called to rescue the brother of the female lead, who dies in the Trench and the Megalodon is freed. There 2 Megs, the smaller male and the bigger pregnant female, who does all the surface killing and is killed but leaves 3 pups. 2 are eaten by other sharks and the one rescued is a female, Angel. She is the star of book 2 and 3. I'm on book 4, where we have her and 5 of her survivingoffspring, all females.
