Nightspark, by Michael Mann

I very much enjoyed Ghostcloud, by Michael Mann, the first book in the duology (? maybe there are more adventures to come) that now continues with Nightspark (Peachtree 2023). Luke has been reunited with his family after foiling the evil plots of Tabitha, who used enslaved children, such as Luke and his best friend Ravi, as well as captured ghosts for her power station in an alternate England. He even has the job as a junior detective he always wanted.  

But he can't settle into ordinary life.  For starters, Tabitha has started on a new evil plan over on the continent, and his best friend Ravi is still her prisoner.  On top of that, Luke is a half ghost, and though he tries to enlist the aid of the Ghost Council, they are hostile to him and think he'd make a better 100% ghost.  But Luke is nothing if not determined, and so with a mixed lot of reluctant helpers and friends, including his best ghost friend, a mission to rescue Ravi and foil Tabitha is launched. 

It seems hopeless, but a string of daring adventures takes the little band across the English Channel...where things get even more dangerously exciting. It's not just extravagant adventure though; sprinkled into the story are thought-provoking moments where the characters have to make hard choices--like an encounter with an overloaded boat of refugees in the Channel, and the question of whether someone who has done horrible things can become trustworthy....

If you like action-packed adventure with supernatural shenanigans, dystopian settings, and brave kids full of heart triumphing over horrible circumstances, you will love Nightspark! But it is essential to read Ghostcloud first (and since I liked that one even more than its sequel, I'm sure you won't mind at all).