Josef K. is suddenly arrested in his room at his lodging house on the morning of his birthday. Two police stooges inform him of the fact: 'It's the law. How could there be any mistake?' they parrot in their ignorance of the grounds for arrest. Some sort of informal bail seems to be involved since K. is free to go to work at his bank and otherwise live life as usual. I say 'free' but this drama, faithfully adapted by director Justin Fehr from Franz Kafka's novel of 1914/15 but only published in 1925 after his death, directs its piercing gaze at the limits of personal freedom both within a totalitarian state and within the psyche of a hyper-sensitive man, prone to doubts and insecurities.

When K. subsequently arrives at the police office, our disquiet at the arrest is confirmed by the amusement of the officer – significantly a bureaucrat rather than a policeman - at the very idea that K. wishes to contact a more senior official of his acquaintance. For this is a world reminiscent of Dante's Nine Circles of Hell, where those accused find themselves faced by a process (alternative meaning of the usual 'Trial' translation) apparently designed not to investigate and elucidate the truth, but rather to frustrate, to frighten, to exhaust and in the end to crush its victim, caught in its meshes like a bluebottle by a tarantula spider.

Thus in scene after scene K. grapples with an imperfect understanding of the law in this topsy-turvy world; its procedural gateways and the paths through its wilderness, each one monitored by cynical lawyers galore and moribund bureaucrats fearful of committing themselves to any view of higher authority or of suggesting a course of action. All take for granted K.'s arrest and his subsequent descent down an ever-moving staircase to perdition. They like to categorize themselves as mere catspaws of nameless seniors existing in a penumbra ever out of reach.

The production takes us from K.'s rented room to the denouement at a cemetery via a series of offices and, startlingly, a cupboard which when opened reveals three men in the process of being flogged by a sadistic guard; 'I am here to whip people and whip them I shall!' he tells the remonstrating K. We also visit K.'s office at his bank, the floor strewn with papers pertaining to his hopeless defence, then on to a church. The playing space is, as always here, tiny, but Justin Fehr and designer Oleksii Melnyk have managed by virtue of a few simple props and the sheer intensity of the action and acting to make each perfectly distinctive and contributory to the overall effect. Thus a portrait painter in his studio, visited by K., is revealed to be a charlatan, a regime lackey who manages to sell K. a portrait that turns out, with metaphorical significance, to be perfectly blank. This is a detail not in the novel but one imagined by Justin to great effect.

As K., Odysseus Alivertis, a twitchy figure in chalk-white make-up, delivered a performance of harrowing truth and even managed to look a bit like Franz Kafka. When he declares with absolute conviction that there can only exist proceedings against him if he acknowledges them as such, he achieves a touch of nobility that he retains throughout; and his contribution to the final scene verges upon the truly heroic. His appeals delivered directly to the audience rather than to his interlocutor are poignantly effective since he seems to desire validation or even rebuttal from an external reality.

The remainder of the cast of six, playing 17 rôles between them, turn in a marvellously collaborative effort. It seems invidious to single anyone out, but in the demanding part of Leni, a sort of court groupie and who becomes K.'s lover, Ruth Eichinger in rose-patterned black tights was as sexy and passionate as can be in a painful scene that I take to be a working-out of Kafka's own sexual impotence. Leo Maedje was especially boldly-spoken as an unctuous lawyer in an emblematic wheelchair, and Henrique Laitenberger's supine grovelling as Block, a fellow-accused employing six lawyers, was appallingly real.

The English subtitles were snappily projected and literate, while both lighting and music were as effectively chosen and placed as I've ever seen in a student drama. Thus when K. enters the court waiting room, it is characterized by unsettling yellowish-green light and electronic music that seems to press against the folk held there. The lighting varied constantly between gloomy and dazzling, and as the anxiety in K.'s psyche was ratcheted up, so the pulses of the music became ever more insistent.

Kafka once said that books were not worth reading unless they shook readers out of their stupor and forced them to pay attention. This opening night audience was gripped from start to finish, and at the end the applause went on and on and on. The rest of the run is sold out - fortunate are those folk in possession of a ticket for this little gem.