Mervyn Peake’s magnificent Gothic trilogy taxes the imagination on the page – so imagine how much more difficult it is to bring his weirdly conceived characters to life on stage, with a set consisting of nothing but bare floorboards and the backdrop of a section of Oxford’s ancient city wall.

This was the challenge which director Tara Isabella Burton set herself. Over Christmas, she adapted Peake's trilogy for stage. From the vivid pageant of characters paraded last night - and the multiple scene changes - the running time of two and a half hours was tight. And this was student drama.

The cast’s principals seemed to draw heavily on Burton’s previous production of Anthony and Cleopatra, with Michael Crowe’s Steerpike morphing quickly from grubby kitchen rat to eloquent courtier (sometimes a shade too floridly). His ease on stage, daring line delivery and physical grace contrasted with Charles Macrae’s Titus Groan, whose evening began shakily, but improved as he grew in confidence. By the last gruelling physical duel, Titus and Steerpike were well matched.

Alex O’Bryan-Tear’s grave Sepulchrave’s descent into madness was movingly portrayed. Who (except Peake) would have conceived that a fire destroying Sepulchrave’s beloved library would result in the 76th Earl of Gormenghast believing himself to be an owl – and demanding to be fed raw, fat mice?

Steerpike’s manipulation to arson of Sepulchrave’s disgruntled twin sisters, Cora and Clarice, was a masterpiece of puppetry. Clio Doyle and Sarah Jones’ ventriloquism was superbly timed.

Peter Rhodes as Flay - the loyal servant banished unjustly - brought a depth and sympathy to the role which extended beyond the character’s relatively brief appearances on stage. Whether cowering in caves, lurking in dungeons or creeping down corridors, Flay was a light-deprived beacon of loyalty. Sam Young’s Prunesquallor brought all the qualities of a good egg, with a high, tinkling laugh, which - when faced with his vain sister Irma(Alice Young)’s excesses - verged on the murderous.

Jessica Law’s Fuschia was outstanding. She brought strong-willed childhood to an adult world, and yet her pity for her father’s condition (portrayed as she drew books in chalk beside him to recreate lost tomes), her ambivalent attitude towards Steerpike (who aroused her latent sexuality) and her loyalty to her family was freshly drawn through a beguiling array of child-like responses which were both truthful and striking. Fuschia is an original - and so was Law’s performance.

The magnificent Gertrude (Kit Rees) held sway over Gormenghast, staying true to its principles and traditions, preferring her cats and birds to her children, but without compromise, and with a nose for villainy - plus a ruthlessness and willingness to pluck out ‘its dark root’ herself, regardless of the activity of all her bizarre retainers. Her flinty visage and tough resolve showed she was the true Keeper of the Stones.

Francesca Petrizzio’s costumes were dazzling – Peake himself might have wished he had sketched them.

Richard Owen’s lighting vivified the bare stage. Gormenghast came alive last night.