Never Let Me Go gives you puzzle pieces about the lives of its characters that need to be put together, and it's a rewarding journey putting them together. 

The latest production at the Bristol Old Vic is based on the famous award-winning novel by British author Kazuo Ishiguro and has already been adapted into a film. 

It has been adapted into a play by Suzanne Heathcote of Killing Eve fame, who has a wealth of complicated themes and ideas from the book to play with and unpack. 

The first-person narrative of the book is chopped up and dispersed across different timelines with our main character Kathy, played by Nell Barlow, who is the filter through which the story - and its dystopic nature - unveils itself. She's kind, positive and optimistic, becoming instantly likeable 

Through a combination of real-life and flash-backs of memories both internally from within Kathy's mind and externally as she tells a story to someone she is 'caring for' we learn more about Kathy as a person and we learn about the world we're watching. 

(Image: Hugo Glendinning)

The set, made up of big floor-to-ceiling panels that are subtly lit has been carefully designed to convincingly appear as both a hospital or a school, and for one moment on a beach, it opens up in quite a powerful moment. 

For those who had read the book or watched the film, the unfolding mystery of the production which builds to a climax and big reveal of the reality of what our characters are and the horrific and problematic nature of their existence might be dampened, but for everyone else it's an effective slow-build towards it. 

At the centre of this is a love triangle between Kathy, best friend Ruth, played by Matilde Bates and mutual love interest Tommy, played by Angus Imrie. They are superb together and really help to capture the emotionally resonating love that underpins the main conceit of the whole show - what is it to be human? 

It focuses on love, creative expressions through art and the ethics and morals of humanity but manages to stray from becoming too heavy or overwhelming in tackling these themes while still maintaining the emotion and poignancy of the novel. 

It was a little slow and ponderous at times, with some acts being a little overlong and some may struggle to grapple with the deliberate ambiguities of what happened to create this scenario, but when you have performances as strong as Never Let Me Go had, working with some excellent source material you're still left with a thoroughly excellent play.