Oppel's characters are incredibly complex, with the possible exception of Victor and Konrad's mother who is often peripheral, though still strong when she shows up and all seem to have some dark secret that motivates them throughout the novel. What starts out as an innocent quest for a medicine to cure Konrad quickly turns into a dark and twisted game of survival, secrets, and deceit, and the further they all continue, the less likely it is that any of them will actually win. This book is a work of fiction that goes beyond the limits of a simple prequel, often seeming as if Mary Shelley, herself, might have imagined the world and history of the Frankenstein family that Oppel has created. Oppel's mastery of language, and his ability to provoke a multitude of emotions, shines through, in This Dark Endeavour: The Apprenticeship of Victor Frankenstein

– Highly Recommended. (4/4 STARS)

Love, loyalty, loss, and obsession, all linger at the heart of Kenneth Oppel's This Dark Endeavour: The Apprenticeship of Victor Frankenstein , a gripping narrative of the early years of Mary Shelley's Dr. Frankenstein, his family, and the passions that ultimately consumed him. I am often wary of prequels to classic novels, but I have to admit that I was pleasantly surprised and more than a little short of breath by the time I read the final sentence of this, dare I say, masterpiece. Having recently read Shelley's Frankenstein , I was not entirely sure how this attempt at a childhood story of the mad doctor would turn out. Hours after finishing the novel, I am already anxious for another installment.... 

– CANADIAN MATERIALS (Starred Review)   

Brash, jealous, and arrogant, Victor is sweet relief from today's introspective YA protagonists, and one can easily visualize how this teen becomes the mad genius of Shelley's Frankenstein.

– BOOKLIST

Sharp readers will find allusions to Mary Shelley, her literary circle, and classic horror films; for those simply wanting a good story with plenty of action, this book will not disappoint. Many details remain the same as in the original work; for instance, Victor's arrogant desire to overcome the power of illness and death makes him a slightly unlikable protagonist. But here's a sign of a good storyteller: readers may not like Victor, but they will certainly want to find out what happens to him. 

– SCHOOL LIBRARY JOURNAL

This prequel to Mary Shelley's Frankenstein has nothing of satire or parody to it; it builds faithfully on the spirit of the original as it imagines the episode that planted in the adolescent Victor Frankenstein the seeds of the adult scientist who would create and then reject a monster. Oppel (Half Brother, BCCB 10/10) posits a twin for Victor: Konrad, smarter, stronger, and kinder than the mercurial Victor, and an emerging rival for the affections of their distant cousin, the fierce and capable Elizabeth. When Konrad falls mysteriously ill, Victor's search for a cure leads him (along with Elizabeth and their phobia-ridden friend Henry) into the bowels of Chateau Frankenstein, where a hidden library starts him on the study of alchemy and a desperate race against time (and human fallibility) to create the Elixir of Life. There is a questing element to the trio's struggles to obtain the three ingredients needed for the elixir, each of which must be acquired through escalating feats of daring, that keeps the pace tripping urgently along, while the atmosphere is pure old-school cinematic horror, all hidden stairwells, ancient dungeons, and creaky, cobwebbed doors. Spare, formal language is well suited to the material, giving it a sense of connection to the original without alienating modern readers. The novel also shares its source's underlying anxiety about the shadowy intersections of faith, science, and magic in a world teetering on the precipice of a level of scientific endeavor that seems akin to playing God. Dark psychological drama, though, is the main engine here: Victor's determination to succeed is as much an urge to outperform Konrad as to save him. Oppel grapples with the human duality of animal and soul in ways that recall (but don't repeat) Shelley's similar thematic explorations as he revitalizes the classic horror tale for a new generation.

– BULLETIN OF THE CENTER FOR CHILDREN'S BOOKS (Starred Review)

This Dark Endeavour has all the elements - a love triangle, the supernatural, a touch of animal lust - that made the Stephanie Meyer franchise such a hit.  It also has depth and intelligence.... Most engaging of all is Oppel's choice of narrator. Victor's seething passions and mixed motives - coupled with his clear-eyed assessment of them - make him by far the most complex and, oddly, sympathetic character Oppel has created (at least, among those that are human). Kind, sensible Konrad seems positively pale by comparison. Team Victor, start your engines.

– QUILL & QUIRE

This Dark Endeavour by Kenneth Oppel is a brilliantly layered exploration of what made Victor Frankenstein the man he became. When Konrad, Victor's �better� twin, falls mortally ill, Victor turns to the secret Dark Library in Chateau Frankenstein and the forbidden arts of alchemy to find a cure. Victor's struggle to pit fraternal love against his baser emotions, particularly his animal attraction to their cousin Elizabeth, who loves Konrad, gives a compelling psychological edge to this richly imagined Gothic thriller.

– TELEGRAPH (UK)

Konrad and Victor Frankenstein, fifteen-year-old identical twin brothers and best friends, live with their family in a chateau just outside of Geneva in the late 1700s. Konrad is sensible and charming, whereas Victor is rash, headstrong, and arrogant. When Konrad contracts a mysterious illness the doctors are unable to cure, Victor, their cousin Elizabeth Lavenza, and their close friend Henry Clerval search for an answer in the Dark Library, a secret room inside the chateau where they discover alchemist Cornelius Agrippa's Elixir of Life recipe. In a race against Konrad's failing health, the three friends repeatedly risk their own lives to track down the elixir's ingredients. Secrecy, a love triangle, and ultimately deception complicate this dangerous quest, but as Oppel makes hauntingly clear, it is Victor's intense desire to save Konrad's life, no matter the cost, that propels the novel's action. As a prequel to Mary Shelley's gothic classic Frankenstein, this is both meticulously researched and highly original, with the invention of Konrad providing a provocative backstory. The story continually hints at how the brothers' personality differences and Konrad's illness will inevitably lead Victor down the dark path that consumes his adult life. Written from Victor's perspective and filled with his believable internal moral struggles, Oppel's novel is a gripping tale of undying devotion, mixing hope with foreboding.

– CYNTHIA K. RITTER, HORN BOOK (Starred Review)

Adventures do not come more thrilling, gorgeously written, or absorbing than this."

- Amanda Craig, LONDON (SUNDAY) TIMES 

Oppel has reinvented the gothic thriller for modern readers. The narrative crackles with tension, emotions run high, and the atmosphere is perfectly dark and brooding. The Shelleys would be proud. I definitely recommend you check out the book when it's published August 23. I anticipate This Dark Endeavor will get a lot of attention, and rightly so.

– RICK RIORDAN (Author of the bestselling Percy Jackson series)