Two years after its debut, “Percy Jackson and the Olympians” has returned for a powerful second season that stands just as tall as the first. Season 1 followed the snarky and precocious demigod Percy Jackson (Walker Scobell), who discovers his lineage as the son of Poseidon (Toby Stephens) and embarks on a mission with his best friends, Annabeth (Leah Sava Jeffries) and Grover (Aryan Simhadri), to restore Zeus’ stolen thunderbolt (Courtney B. Vance replaces the late Lance Riddick in Season 2). In a darker Season 2, which boasts much higher stakes for the trio, Rick Riordan’s expansive world is only getting juicier and more robust.

The eight-episode season (critics received four for review) opens one year after the events of the Season 1 finale. It’s the last day of school, and Percy is eager to return to Camp Half-Blood, but things are a little trickier this go-round. His mother, Sally (Virginia Kull), has begun fostering a Cyclops named Tyson (Daniel Diemer), and he’s on edge because he’s heard nothing from Grover or Annabeth all year. Though Percy has eagerly written his friends to stay in touch, they haven’t responded.

For Percy, returning to Camp Half-Blood isn’t exactly the magical reunion that he expected. Not only is Tyson still lingering, but Grover is missing and apparently in grave danger. Meanwhile, Annabeth is acting odd and standoffish, and Chiron (Glynn Turman) has gone on vacation and left the camp in the incapable hands of Mr. D (Jason Mantzoukas) and the villainous Tantalus (Timothy Simons). Even though Half-Blood is clearly under attack by the forces of Kronos (Nick Boraine), the two men ignore the threat and instead are hyper-focused on a preposterous chariot competition. The race is the least of Percy’s concerns. Instead, he’s set on partaking in an unsanctioned quest to the Sea of Monsters to save Grover and retrieve the Golden Fleece.

Yet this isn’t a straightforward adventure. Aside from Disney+’s Marvel and “Star Wars” slates, “Percy Jackson” remains its standout series, especially for tweens and young teens. Unlike the books’ film adaptations, which were widely lambasted, this iteration of Riordan’s universe works because it began with a younger cast, allowing them to grow and develop on-screen (Scobell has literally grown a foot since we last saw him). Notably, it showcases a multicultural world (Simhadri and Jeffries are Indian American and Black, respectively), one that offers a new generation of young viewers the chance to see themselves represented on-screen. (When the cast was announced, the racist vitriol was so nasty that Riordan called it out publicly.) If there were any doubt, the emotional depth and vigor depicted by the entire cast prove that these were always the right actors for the roles.

As in Season 1, “Percy Jackson” continues to be packed with action, now with greater intensity. The second season takes place mainly on the high seas, with terrifying creatures and a looming war between the Gods and Kronos’ army. The characters’ friendships, feelings and perspectives mature, and the show highlights these growing pains. With Grover out of pocket, Annabeth and Percy must reconcile the fractures in their friendship and find ways to be accountable to one another — despite their differing worldviews — so they can move forward.

Friendship and the desire to belong remain at the forefront of the show, anchored by the lore and history of the mercurial Greek gods and the stellar performances of the leads. Above all else, “Percy Jackson” remains a series about having the courage to stand up for yourself and your loved ones, amid the horror and beauty of what it means to come of age.

The first two episodes of “ Percy Jackson and the Olympians” Season 2 premiere Dec. 10 on Disney+, with new episodes dropping weekly on Wednesdays.