Here is the summary of the book:
The Secret Cipher is the sequel to The Secret Box, a rollicking adventure full of family rivalry, magic, questing, and laugh-out-loud humor that's perfect for fans of Dan Gutman, Wendy Mass, and Trenton Lee Stewart.
Jax Malone and her cousin Ethan Hoche were not expecting one of Jax's birthday presents to contain a dangerous magical object from a mythical past: an urn with the dark power to suck hope out of the world.
Though the first urn is safely hidden, there are two more urns that could rid humanity of both faith and love. And powerful enemies who want to find them and use them to control the world. Now, even though they were never meant to open the present and discover its secret, Jax and Ethan must race to find and destroy the two remaining urns before it's too late.
Jax, Ethan and Tyler return for yet another adventure. Jax's birthday present changes their lives. All those stories are true. The Greek Mythology holds true. The Gods exist and most of all certain things, myths of legends are real and are powerful beyond all imaginations. The urn of hope maybe safe but two more still remain. Faith and Love. Two more urns that may just be more powerful than their third counterpart.
I'd say the author did a decent job expanding on his universe. There is a definite character development evident in this sequel. Jax is a bit more cautious, although still very much the energy freak. Cousin Ethan is still the factoid geek but a bit more confident and Tyler, still the designated driver. Things just have escalated now. Godly intervention is expected now that those urns have come to light and secrets from the past reveal the potential for even great changes. An action-packed sequel and a fast page turner ..... We are more than invested to learn what the fate of our heroes is and what happens next.
"A quick and fast paced sequel"