Geoffrey Dutton 
Her Own Devices [EPUB ebook] 

After witnessing a kidnapping in gritty Piraeus, Greece, a Swiss ex-pat and ex-activist with an energetic five-year-old son vows to put the culprit, his swaggering partner, and the cop protecting them, out of business, relying on home-brew surveillance devices and a loose coalition of allies. All the while, an ethereal narrator – the spirit of the boy’s late father, denied entry to Paradise – worriedly surveils them. He seeks to unite them with his long-lost brother, but lacks agency. Barely surviving her flash mob’s climactic confrontation with the bad guys, our heroine learns that you never know who your friends are until you need them, and even then you still might not know… but that’s okay.