This post was updated Oct. 3 at 11:31 p.m. 

The newest “Percy Jackson” book is perfect for its original middle grade audience and older readers who stuck around to sip from the chalice.

“The Chalice of the Gods,” which was published Sept. 26, is a welcome addition to Rick Riordan’s mythological universe. Filled with equal parts nostalgia and novelty, it is a masterclass in effective sentimentality. This sixth entry in the “Percy Jackson and the Olympians” series is told from Percy Jackson’s point of view as the son of Poseidon tackles the most dangerous quest of all – college admissions.

Because Percy is not an ordinary high school senior applying to ordinary mortal colleges, he must embark on a similarly unusual mission in order to obtain godly letters of recommendation. Joined by his girlfriend and daughter of Athena, Annabeth, and his satyr best friend, Grover, Percy assists Ganymede, cupbearer to Zeus, in locating his missing chalice and runs into other deities as the group takes on a new adventure.

While several of the author’s other books are told from various third-person perspectives and feature a larger ensemble, Riordan brilliantly limits the number of characters in this entry. By keeping the story centered on the trio from his first “Percy Jackson” novel, “The Lightning Thief,” readers are better able to enjoy the interactions between the three leading characters and a tighter, more focused story. Coming in at 256 pages, the plot zips along at a rapid, enjoyable pace without feeling rushed.

The book’s premise is a warm love letter to returning readers who grew up on Riordan’s books as children and are now young adults themselves. “The Chalice of the Gods” has many of the same elements of the first novel, which was published in 2005. It retains the three core characters, and even the driving conflict – a godly item gone missing – is the same. But nearly two decades after the original, Percy is on the cusp of adulthood and thus a little bit wiser, which is reflected in his character arc.

This doesn’t mean that the book is atypically heavy-handed. Riordan, a master at balancing snarky and sweet, keeps it light with the signature sarcastic first-person narration that elevated “Percy Jackson” above its literary contemporaries. By reading Percy’s unfiltered commentary, readers receive equal doses of hilarity and heart and get to peek into the head of a character who has grown up alongside them. Likewise, Percy wrestles – quite literally – with growing older, ponders new responsibility and questions his plans for the future. Such themes are not exclusive to demigods.

At times, “The Chalice of the Gods” reads like a character study. The external stakes are smaller, and the antagonists are more funny than frightening, yet the lack of apocalyptic undertones makes this the most relatable “Percy Jackson” book. Most people haven’t crossed swords with Greek immortals, but many know the struggle that accompanies college applications and an unclear future. Even the son of the sea god drowns in the depths of the unknown.

With the recent onslaught of reboots and franchise sequels, skeptics might dismiss this novel as a similar cash grab designed to prey on the nostalgia of its now-grown fanbase. But Riordan sticks to the emotional center of his characters, honing in on the qualities that endeared them to readers in the first place. Unlike other long-awaited sequels, Percy, Annabeth and Grover feel true to character. More importantly, they continue to help readers reflect on their own lives in a way that feels profound, not phony.

While the ancient-turned-modern premise, heroic escapades and hilarious banter certainly boosted its popularity, the “Percy Jackson” appeal was always about friendship and humanity. “The Chalice of the Gods” succeeds because it keeps those qualities at the forefront. Any hint of resulting nostalgia doesn’t feel forced, but earned.

Despite godly guest stars and Olympic-sized adventures, “Percy Jackson” shines through its mortal heroes who keep the fantastical mythos grounded and relatable, and “Chalice of the Gods” is no exception.