I'm not 100% sure which 'peril book' you mean—there are a few out there with 'peril' in the title. If it's the middle-grade adventure novel 'Peril at End House' by Agatha Christie? No, wait, that's 'Peril at End House,' but that's Poirot. Maybe you're thinking of something else. Honestly, my mind jumps to 'A Perilous Passion,' which is a Regency romance by Anthea Lawson, but the plot there is pretty straightforward: a headstrong botanist heroine gets tangled with a spy posing as a rake, with the usual society gossip and danger. But if we're talking peril as a general concept, that's too broad.
If I had to guess the most commonly searched 'peril book,' it might be 'Perilous Times' by Thomas D. Lee? That one's a recent fantasy where King Arthur keeps resurrecting whenever Britain's in danger, and he's just so tired of it. The plot follows him teaming up with a queer punk knight named Mari to take on a modern corporate evil that's poisoning the land. It's less about a single peril and more about cyclical history and environmental decay. The magic system with Excalibur and the Lady of the Lake is cool, but the pacing felt uneven to me—the middle drags while the characters argue about capitalism.
Actually, the phrase makes me think of an old kids' book I read, 'Peril in the Palace' from the 'Imagination Station' series. That was a time-travel adventure where two kids go to ancient China. The main plot was them trying to retrieve an artifact while avoiding palace intrigue. It was fine for what it was, but not exactly a literary heavyweight. Without a specific author, it's hard to pin down 'the' peril book. My advice would be to check the full title or author next time; otherwise, we're all just guessing in the dark here.