Dennis Clegg is in his thirties and lives in a halfway house for the mentally ill in London. Dennis, nicknamed "Spider" by his mother has been institutionalized with acute schizophrenia for some 20 years. He has never truly recovered, however, and as the story progresses we vicariously experience his increasingly fragile grip on reality.
In Britain, Dennis Cleg has just been released from a psychiatric hospital, and upon the recommendation of his physicians has moved into a halfway house catering to psychiatric patients, the house run by the prickly demeanored Mrs. Wilkinson. His release was despite he still being in a somewhat catatonic state due to his issues. When he was a child, Dennis was nicknamed Spider by his mother because of stories she told him about spiders, and as such he has always been fascinated especially by webs and spider silk. Although he does not speak about it to either Mrs. Wilkinson or his housemates, Spider continues the thoughts that led to his psychiatric problems, namely how he saw his working class parents as he was growing up, and how his view specifically of his mother began to be sexualized in seeing his parents together. In these remembrances, Spider externalizes his view, as if he is looking at them, others and himself as a bystander, albeit one who cannot intervene in the proceedings. He also continues to transfer his mother's image onto other women of a certain type, such as onto Yvonne, who was a barfly and tart at the pub where his father often frequented. These continued thoughts may affect his viability of living in the outside world.
A mentally disturbed man takes residence in a halfway house. His mind gradually slips back into the realm created by his illness, where he replays a key part of his childhood.
- Opening in the East End London in the 1950s, a deeply disturbed boy, named Dennis Clegg, nicknamed Spider (Bradley Hall), 'sees' his father (Gabriel Byrne) brutally murder his mother and replace her with a prostitute, Yvonne (Miranda Richardson). Convinced they plan to murder him next, Spider hatches an insane plan, which he carries through to tragic effect.
Many years later, an adult Dennis 'Spider' Clegg (Ralph Fiennes) is released from a local mental institution and is given a room at a local halfway house catering to mentally disturbed persons. Clegg receives little care or attention from the landlady Mrs. Wilkinson (Lynn Redgrave). Clegg, in his new abode, starts piecing together or recreating in his memory to try to remember an apparently fateful childhood event. During the days, he roams the nearby derelict urban area and the local canal and starts to relive or visualize a period of his childhood with his mother and his father.
A shift takes place in the child's psyche when he witnesses his mother groping with his father in the garden and, subsequently, when he sees his mother in a silky night gown she wore for his father. The son, as a grown man seems to recreate in his memory the buildup to his father's murder of his mother with the passive support of a prostitute he is involved with, who then moves into the house and is presented as his mother. The young son then kills the mistress by gassing her in the kitchen. After that memory he attempts late one night to kill the landlady whom he sees alternatively as the mistress and his mother, but backs away after she says, "What have you done Mr. Clegg?" In the final scene, Clegg is arrested by the authorities and taken back to the asylum.