The addict is Rona (Saoirse Ronan), whose life in London as a microbiologist ... inferring yet again the shaky base from which Rona has had to find her feet. Essiedu is "as moving as Ronan ...

A retreat to more elemental living, planting two feet back on the land of her birth, proved a miracle cure. She’s played in this film adaptation – renamed Rona – by Saoirse Ronan ...