Time traveler Jon Sinclair returns to the 17th century to find the lost city of Atlantis in the second installment of Copus’ (BlackHeart’s Legacy, 2012) middle-grade adventure series.

It’s been three years since 15-year-old Jon fought with pirates in 1692, and now he’s back in the present. He reads a letter from his friend, Capt. BlackHeart, which hints that the captain is able to take him to Atlantis. Jon, his “Pappy” Alistair, his godfather, Nikos, and an English BlackHeart descendant named Colin all hop aboard the space-time-bending ship Carousel and journey to 1699 Crete. There, they reconnect with the captain, who tells them that he may have the key to the legendary lost city. But that key, a black opal stone, is part of a set—and the group will need to find at least one more opal before they can make the Atlantean journey. BlackHeart, however, then encounters an old pal whom he thought was dead. The man also knows far too much about his expedition, which can only mean that there’s a traitor among the captain’s group. This is a sequel that does everything right. For starters, it features several returning characters, such as former navigator Spider and quartermaster Mr. Token, and recognizable predicaments, such as a harrowing battle at sea. But Copus truly expands the Sinclairs’ world by opening up subplots that the preceding novel merely teased. For example, there’s much more back story this time concerning Jon’s long-deceased parents, particularly his father, Weston, who worked for the government’s Office of External Affairs. Similarly, further details about the Carousel suggest its possible origin: the Kimmerii, men from the future who need the ship to return to their own time, a few centuries hence. Unfortunately, Grammy, aka Kathryn, a featured player in the last book, has a much smaller role, but new character Haley, Colin’s little sis, almost fills that void. She’s a brilliant hacker who’s close to Jon’s age, and her addition adds romantic possibilities to the story. Copus has great fun with timeline-divided culture; BlackHeart’s hilarious fascination with a Post-it Note, for example, is a standout moment. There are a few other tasty morsels as well, including a contemporary car chase; a vicious, human-sized falcon; and an ending that leaves at least two characters’ fates in question.

A sensational, exhilarating adventure that will make new readers want to read the series’ first.

In the first book of debut author Copus’ planned series, a boy and his grandmother travel back in time to hobnob with marauding pirates in search of hidden treasure.

Clearly familiar with what should constitute the building blocks of a kid-friendly adventure story, Copus begins the book with a seemingly foolproof plan gone disastrously awry. Alistair and Kathryn (Grammy) Sinclair—12-year-old Jon’s grandparents and full-time guardians following the mysterious deaths of his parents in a plane crash—are gearing up to send Jon to 1776 Philadelphia to witness the signing of the Declaration of Independence. While retired NASA employee Alistair won’t be joining them in the silver time-travel capsule Carousel this time around, Grammy goes along for the ride to prevent any mishaps. But with a loud whirl and a classic sci-fi jolt, the ship’s malfunctioning navigation device instead sends them crashing to the shores of 1692 Port Royal, Jamaica, kicking their journey into high gear. Soon, Jon is kidnapped by the crew of the Black Opal, led by the notorious Captain BlackHeart. Grammy—disguised as a boy named Gramm—gains passage as a cook on the ship of BlackHeart’s conniving rival, Shark Scar, in hopes of somehow crossing paths with Jon. As the novel picks up speed, so too do the cleverly hidden surprises. BlackHeart isn’t as nasty as he initially seems; it’s easy to root for him and his devoted crew during treasure dives and explosive battles with warring buccaneers, especially since he’s taken the ever-trusting Jon under his wing. Gramm’s grandmotherly resourcefulness in winning over Shark Scar’s mutinous, scurvy-inflicted crew never feels unbelievable, and one character’s just-in-the-knick-of-time appearance adds an element of urgency to an already deliciously thrilling finale. The cliffhanger ending foreshadows an exciting voyage to the lost city of Atlantis.

Middle-grade readers (boys especially): Don’t dillydally; grab this nearly flawless book.