While not a "Harry Potter"-sized hit, 2010's "Percy Jackson & the Olympians: The Lightning Thief" performed well enough at the global box-office to justify a sequel - and now the exposition-heavy first trailer for the follow-up has arrived.

"I learned that the gods of Olympus are real. And sometimes they have children with humans, called half-bloods. We're pretty much like anyone else you'd meet...but with a few notable differences. [Cue shot of a Cyclops] We live in the only place that is safe for our kind...until now."

Dun-dun-dun...

The "big bad" in question in this second installment of the series is "Kronos," the Golden Age leader of the Titans who was overthrown by his sons Zeus, Hades and Poseidon and is now intent on exacting "his vengeance on Olympus and the world." The only thing that can save "Camp Half-Blood"? The Mythological Golden Fleece, located in the titular Sea of Monsters.

The trailer itself (which premiered exclusively on MTV.com) packs quite a punch thanks to a collection of dazzling CGI imagery, with shots of several massive creatures including a rainbow-colored water horse known as a "Hippocampi" and a giant horned beast with red eyes that appears to be rather less than friendly. Also in store: an otherworldly transport vehicle known as the "Chariot of Damnation."

My grade for the trailer: B+. After checking it out below, you can rate it for yourself at top left.

"Percy Jackson: Sea of Monsters" is scheduled to hit theaters on August 16.