Every night at 11:11, the lighthouse calls to three ships that sank a hundred years ago. And every night, something answers.

Twelve-year-old June Halvorsen has moved so many times she's stopped unpacking. Then her great-aunt Hester leaves her family a crumbling lighthouse on the stormy shore of Lake Superior, along with a puzzling note: Ask it the right question.

"It" is Lantern, the lighthouse's AI keeper. Lantern learned to talk from a hundred years of old logbooks, so it sounds like a gruff sea captain and recommends cocoa for almost everything. And every night, it taps out Morse code to the Isabel Crane, the Callista and the Margaret Rose, three freighters lost in the great gale of 1925.

The ships answer back.

With her little brother Pip and Theo, a shipwreck-obsessed friend who's terrified of deep water, June sets out to crack the code. What they find isn't a ghost story. It's a secret Hester spent years guarding, and a danger hiding under the waves that could put real ships and real people at risk.

But time is running out. The county wants to buy the lighthouse, Mom is ready to sell, and the Coast Guard is deciding whether Lantern can be trusted to keep the light at all. When a November gale slams into the point with Theo out on the lake, June and Lantern have one night to prove what a girl and a machine can do together.

The Lighthouse Keeper's Code is a warm, gripping mystery for ages 8 to 12, full of real science a kid can try, a family learning to stay, and the best AI friend a lighthouse could ask for. It's perfect for fans of hopeful adventures where kids solve the puzzle themselves.

Some lights are worth keeping.