The Assassin's Curse, by Kevin Sands. Aladdin, Simon & Schuster, 2017. $12.99 ages 12 and up

"Is it?" the king said. "Think. This one" -  he pointed at me - "has now stopped not one, but two plots against my family - plus that business with the plague. He treats poisons, finds criminals - he even deciphers codes. Who better to go than him? And we'd all be dead without his giant friend, rolling pin or otherwise." To my horror, I saw Lord Ashcombe looking at us speculatively ... "

Charles, King of England, has summoned Christopher and Tom to court to praise their bravery and resourcefulness. He has heard about the Cult of the Archangel (The Blackthorn Key) and also of the scam in London (Mark of the Plague) where an unknown apothecary is determined to prove he has a cure for the Black Plague which is terrifying the citizens of London.

While the two are present at court, a plot to kill the king is exposed. However, a cryptic message left behind names the King’s sister, Minette, as the intended victim. Christopher and Tom, along with their partner and friend Sally, are ordered to accompany Minette to Paris, to provide protection. Christopher, a puzzle genius, uses his skills to decipher the code and discover the secrets of an ancient curse on the French throne, as they search for the long-hidden treasure meant to unlock that curse. Christopher constantly refers to the lessons taught and learned while he lived and worked with Benedict Blackthorn, master apothecary.  That connection to the past and the ongoing mention of his Master is welcome.

Above and under Paris streets, the three friends embark on a tension-filled race to find the treasure and thwart an assassination. They don’t always see eye-to-eye as they work together. Tom is right when he accuses Christopher of rushing forward with no thought given to the dangers the three may encounter. Christopher recognizes that Tom has a point; he knows he must make a concerted effort to think before further rash and impetuous action. There is also a hint at the deeper feelings Christopher is beginning to feel for the spunky, skillful Sally. Fans will relish this development, and will also further appreciate the team's continued growth as honorable, often funny, and very authentic characters.

Kevin Sands’ storytelling is remarkable. It is impossible for me to pick a favorite from the first three Blackthorn books. This one has the same strength as the first two, while serving up proof that it will not be the last. The Paris setting, the strong sense of 17th century history, the fast-paced action and complex plot make for a captivating and very satisfying read.

Spoiler alert – it ends in a cliffhanger.

Call of the Wraith is due to be released in late September. I will be waiting in line.