It’s In His Kiss: The Diamond of the Ton Finds Her Match

Rating: ★★★★☆
Genre: Regency Romance
Available On: Amazon (Though if you’re looking for the Illumicrate editions, I’m afraid you’ll need to join the queue of devastated collectors—there’s no new print run planned anytime soon.)

In It’s In His Kiss, Julia Quinn returns to the glittering world of the Bridgertons with the penultimate entry in the series, and this time it’s Hyacinth Bridgerton’s turn to shine. The youngest of the eight Bridgerton siblings, Hyacinth has always been a firecracker—outspoken, clever, and ever so slightly meddlesome. She’s the sort of woman who terrifies most suitors and bemuses the rest. So it’s fitting that her love story is as spirited and unconventional as she is.

Opposite her is Gareth St. Clair—a man with secrets, swagger, and more than a little family drama. Together, they embark on a treasure hunt of sorts, decoding a diary written in Italian by Gareth’s long-deceased grandmother. What starts as an academic exercise quickly turns into an adventure laced with flirtation, frustration, and, of course, romance. This isn’t a love story that simmers quietly—it snaps, crackles, and pops with Quinn’s trademark wit.

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It’s In His Kiss: Plot Summary

Hyacinth Bridgerton, the youngest and most outspoken of the Bridgerton siblings, is clever, confident, and entirely uninterested in simpering through the marriage mart. Her sharp wit and assertiveness make her a daunting prospect for most suitors—until she crosses paths with Gareth St. Clair, a man whose roguish charm is matched only by the secrets he carries.

Gareth is the estranged younger son of the baronet Lord St. Clair. Though raised as the baronet’s heir, Gareth has long been at odds with his father, who despises him and claims Gareth is not his biological son. Gareth’s only source of security is his paternal grandmother, whose affection and financial support have allowed him to maintain a respectable position in society.

Upon her death, Gareth inherits her diary—written entirely in Italian. He’s desperate to uncover its contents, believing it may hold the key to resolving the mystery of his parentage and securing his future. Enter Hyacinth, who reads Italian “moderately well” and agrees to help him translate it. The diary reveals a tantalising mystery: mention of a hidden treasure—family jewels that Gareth’s grandmother once hid to protect them from her husband.

As Gareth and Hyacinth work together to uncover the location of the jewels, they find themselves spending more and more time in each other’s company. Their flirtatious sparring gives way to genuine connection, though both resist the idea of a deeper relationship—Hyacinth because she refuses to settle, and Gareth because of his distrust of marriage and his fear of inheriting his father’s cruelty.

Their partnership leads them on a covert escapade into Gareth’s childhood home, where they search for the hidden jewels under cover of night. The experience brings them closer and forces them to confront their growing feelings.

Eventually, Gareth comes to terms with the fact that Hyacinth is unlike any woman he’s known—clever, loyal, and entirely unafraid to challenge him. Meanwhile, Hyacinth sees the pain beneath Gareth’s bravado and recognises the honour in the man who hides behind wit and charm.

The story culminates in an emotionally satisfying resolution: Gareth and Hyacinth confess their love, and he proposes marriage. The diary’s secret—along with the missing jewels—is only partially resolved in the main text, with a cheeky epilogue years later showing their daughter discovering the hidden treasure in a library drawer Gareth never thought to check.

Why This One Stands Out

It’s In His Kiss departs from the ballroom-heavy backdrops of earlier Bridgerton books, and leans into a more plot-driven romance. The mystery of the diary—complete with secret fortunes and family betrayals—gives the novel a slightly more adventurous tone. But it’s Hyacinth who carries the book. Fiercely independent, occasionally meddlesome, and never willing to settle for less, she’s the heroine many readers didn’t know they needed.

Gareth, meanwhile, brings the brooding-with-a-secret trope to life. His complicated relationship with his father adds depth and moral complexity to his character, even as he tries (and mostly fails) to resist Hyacinth’s charms.

Their banter is electric. Their chemistry, undeniable. But what really makes this novel sing is the way it balances emotional stakes with light-hearted charm.

How Spicy Is It’s In His Kiss?

Spice Rating: 🌶️🌶️

This one simmers more than it scorches—but when it boils over, it’s deeply satisfying. The tension between Hyacinth and Gareth builds through stolen glances, verbal sparring, and all those deliciously Regency-appropriate moments of almost-touching. When they finally give in to their attraction, it’s earned—and laced with emotional vulnerability that makes it more than just a physical connection.

What Romance Tropes Are In The Novel?

Trope Count: 🔥🔥🔥

Enemies to Lovers (Kinda)

Hyacinth and Gareth don’t start out as enemies in the literal sense, but they definitely challenge one another. Their early interactions are marked by sarcasm, teasing, and sharp wit—which slowly gives way to mutual respect and attraction. The tension lies in their clashing personalities and the irresistible pull they try to resist.

If you like your E2L plots to begin with full on ‘I hate your living guts’/’I’m going to physically end you’ energy, this one will disappoint. But it’s definitely a light version of the trope in that they start out with immediate opposition tension.

Secret Legacy / Inheritance

The diary subplot brings an investigative flavour to the story. As Hyacinth translates Gareth’s late grandmother’s diary, clues point to a long-lost inheritance hidden within his family home. It’s not a high-stakes adventure, but the mystery adds intrigue and emotional depth to their growing relationship.

Witty Banter

A signature of Quinn’s style, the banter here is especially sharp. Hyacinth’s intelligence and confidence meet their match in Gareth’s dry humour, creating a delightful rhythm of repartee that underscores their chemistry. If dialogue-driven romance is your thing, this book delivers.

Final Thoughts on It’s In His Kiss

Smart, sassy, and heartfelt, It’s In His Kiss is a Bridgerton standout thanks to its irresistible leads and engaging mystery subplot. While not the steamiest or most dramatic of the series, it’s arguably one of the most fun, with just enough bite to keep it from being fluff. Hyacinth may be the baby of the Bridgerton clan, but her story proves she’s every bit as captivating as her elder siblings.

Fans of banter-driven romance, unconventional heroines, and family secrets will find this one a gem.

Note: If you’re wondering where I got my editions of Bridgerton, they’re Illumicrate limited editions and unfortunately are not currently in print. They’ve done a couple of print runs of this, I missed out the first time, but managed to snag a set on the reprint. If you’re desperate for them try buying second hand on eBay, but otherwise I’d suggest following Illumicrate and keeping an eye out for another print run. BUT be aware the last update they made was to state that they’re not planning to do another run any time soon, so please stop asking!