Assia was my true wife and the best friend I ever had, wrote Ted Hughes, shattered, after the suicide of Assia Wevill and their four-year-old daughter in their London apartment in March 1969. The loss was doubly tragic, as Assia had chosen to leave life just like Sylvia Plath: by turning on the gas and inhaling the fumes.

The only difference was that Assia took with her to death the fruit of her bond with the poet, their four-year-old daughter. Diva, femme fatale, enchantress, muse: the stunningly beautiful Assia Wevill inspired these and many other labels in her short but tumultuous life. However, her fate, which would lead her through three marriages and an unending wander from bleak pre-war Berlin to troubled Palestine and from there to the 'cheerful' London of the 1950s, perhaps best justifies the description inscribed on her grave: Here lies a lover of the absurd and an exile.

The narrative of the complicated relationship between Sylvia Plath and Ted Hughes — the most famous poet couple of the 20th century — typically assigns blame for the tragic failure of their marriage alternately to one side or the other. However, for more than four decades, the third dimension of this failure, equally significant and intriguing, has been overlooked: the presence of Ted Hughes's tragic mistress, Assia Wevill.

This book is the first biography of Assia Wevill. Following the journey that shaped her life, the authors simultaneously shed new light on the Plath-Hughes marriage. However, the focus of the book is the complex and contradictory story of Assia, who was inevitably torn between fateful attraction and obsessive love, fidelity and betrayal, cruelty and tenderness, dependence and rebellion, envy and self-sacrifice.

The two journalists researched Assia Wevill's life for over fifteen years, uncovering personal records, her diaries and correspondence, and speaking with all the key witnesses, many of whom are speaking here for the first time.