NOTo we were more sensitive to the paradoxes of love than the Austrian poet Rainer Maria Rilke. “Unity between two people is an impossibility,” he wrote in Letters to a Young Poet. “But, once the realization is accepted that even between the closest human beings, infinite distances continue to exist, a wonderful living side by side can grow, if they manage to love the distance that separates them.”

This paradox – of twinned closeness and alienation in lovers – is at the heart of Nino Haratischvili’s My Soul Twin., his second novel to be translated into English following the huge success of his award-winning saga The Eighth Life, a 900-page saga that chronicles the fate of Georgia under Soviet occupation and the ensuing struggle for independence. Haratischvili writes in German but was born in Tbilisi, Georgia. Shortlisted for the International Booker Prize, and dubbed “Georgia’s War and Peace,” The Eighth Life has been hailed for its elegance as much as its weight; Haratischvili brilliantly combined social commentary with finely drawn characterization to tell a story of Georgia’s Soviet past that had largely gone unreviewed. Georgians – many of whom are still divided over their Soviet heritage – loved it too.

My Soul Twin, translated by Charlotte Collins, who also co-translated The Eighth Life, is set largely in present-day Hamburg and Berlin and follows a Wuthering Heights-style plot. Stella and Ivo are reunited as children when their parents embark on an affair, and then they too develop a relationship of their own. How to name this relationship remains an unsolved enigma: are they brothers and sisters, lovers, friends, companions, soul mates? All and none of the above, Stella, the book’s narrator, seems to suggest. When Stella talks about who Ivo is to her, the phrase “sort of” is regularly invoked.

Fast forward several years and Stella is happily married to Mark – well, happily in this kind of unhappy suburbia – and they have a boy called Theo. When Ivo, who has become a journalist, returns after an unexplained absence, everything begins to go downhill. Ivo and Stella sleep together before he persuades her to come with him to Georgia, where he’s working on a story mysteriously tied to a traumatic incident from their past. The nature of this incident is not revealed until much later, but its aftershocks are visible and violent. Stella and Ivo appear both remedy and poison for each other, locked in a perpetual dance between “sweet closeness” and “terrible alienation”.

After the first two thirds that alternate between past and present, the novel finds more rhythm when Stella finally agrees to go to Georgia with Ivo. Haratischvili beautifully describes Tbilisi as a place “lost between something past and something to come”, its architectural heterogeneity reflecting the many aspects of the relationship between Ivo and Stella. The city becomes a fictionalized version of what the two could never achieve, a place where two wholes coexist in one: “It seemed to hold the two worlds of East and West stable, uniting them. He swallowed both, but was not poisoned by either.

In Georgia, the big ideas of the novel – the curse of the past, the legacy of trauma, the compulsion to repeat – converge, and the buried secret of Ivo and Stella’s past is finally revealed. Haratischvili brings us superbly to this point in a breathtaking finale. However, this is accompanied by dense psychological diagnoses that err on the side of explanation, execution diluting the strength of the concepts.

My Soul Twin, released in German more than ten years ago, suffers against The Eighth Life; it is over-narrated and sometimes falls into the cliché. “Everything had gotten out of control since Ivo reappeared,” Stella explains after nearly getting into a truck around the same time Ivo returned. A moment like this is too transparent in its intentions, and moreover it is unnecessary, given that Haratischvili – who has also worked as a playwright and director – is so strong on real drama.

The last pages of the novel recall the opening passage of the book but with subtle differences, as if to say that it is possible to overcome past traumas; new words can be written on the seemingly predetermined script of life. It’s a neat, nuanced conceit reminiscent of The Eighth Life’s equally circular ending. Haratischvili’s other three novels have yet to be translated into English. I hope they are, and others unfold among the “acacias and dust” of Tbilisi. This is where his writing feels most sensitive to complexity and contradiction; it is here, on familiar ground, that she finds something new.

My Soul Twin by Nino Haratischvili, translated by Charlotte Collins, is published by Scribe (£16.99). To support the Guardian and the Observer, order your copy from guardianbookshop.com. Delivery charges may apply