It's a follow-up to Life Class, apparently, but it is, inescapably, an offshoot of the magnificent Regeneration Trilogy which made Barker's name and won her the Booker Prize.
The trilogy was about World War I, poetry and mental illness. Toby's Room is about World War I, painting, and facial disfigurement. The art school chums who met at the Slade in Life Class are now exposed to the full horror of mechanised warfare. Kit Neville, the Christopher Nevinson clone, has his face blown off in France and is brought home to Queen Mary's Hospital in Sidcup where the plastic surgery pioneer Harold Gillies does his best to make the facially disfigured acceptable and 'Harry' Tonks, professor at the Slade, draws meticulous records of the process. Gillies and Tonks are obviously real whereas the 'students' are thinly fictionalised. The Bloomsbury Set make a brief cameo appearance - notably and memorably Lady Ottoline Morrell.
The titular Toby is Toby Brooke, brother of the artist Elinor. They are very close - too close, indeed. Toby goes to war as a doctor and is posted missing, presumed dead. Elinor feels compelled to find out the truth. Neville was a stretcher bearer in Toby's unit. Elinor contacts him through fellow student Paul Tarrant, himself invalided out of the front line. They visit Neville at St Mary's where Elinor is recruited by Tonks to assist with his "Rogue's Gallery".
The problem is, the book is in two distinct halves - pre-war and towards the end of the war. It may well be that Life Class forced this structure onto Toby's Room. I don't know but will certainly find out. It makes Toby's Room, as a standalone novel, clumsy and disjointed. The characterisation is, nevertheless, excellent, especially with Neville himself, who is far more interesting than our apparent heroine. And the writing, as always with Barker, is exquisite.
Not perfect, then, but a fascinating addition to the canon.