In Williams’ middle-grade debut, siblings must battle evil all on their own while their superhero parents are away.

Avery isn’t your average middle schooler: Her chores include doing maintenance on gadgets for her dad, Captain Comet, and mom, Nebula Nova—superheroes who are off on a mission as the story begins. When a villain suddenly attacks the city of Neo-Veridian, Avery, along with her brother and sister (Jax and Lina), steps up to fight. The diabolical Malakor is an interdimensional “devourer of worlds,” and the kids will need to use everything at their disposal to stop him, including a handful of glitchy devices stored in their home. They put their skills to use, such as Avery’s leadership abilities, Jax’s mechanical deftness, and Lina’s “energy abilities,” which the family doesn’t quite understand yet. Malakor, meanwhile, systematically targets the city’s power source, feeding on the citizens’ fear as he blankets them in perpetual darkness. While not every plan the siblings dream up succeeds, they refuse to give up until they can rid Neo-Veridian of this formidable menace. Williams’ three charming heroes will surely win over readers. They argue a lot, but never viciously, and they often encourage one another, paying a bit more attention to Lina, the youngest. The story showcases myriad devices (with such snazzy names as “Sonic Disruptor”) that often fail in amusing ways; one unexpectedly erupts into glitter, which gets everywhere. Narrative details are deliberately kept simple; Malakor is more an ominous presence than a tangible threat, turning the sky a “sickly green” and popping up as a creepy voice in the kids’ heads (“You burn so brightly…you will fade just as fast”). Some scenes can be repetitive, typically consisting of the kids talking about devices, many of which are mentioned but not shown in action. Still, this engaging series opener will leave readers eager to see Avery, Jax, and Lina prove themselves.

Capable, audacious kids propel this entertaining SF adventure.