At a stage performance of Othello, a man leaves hurriedly for the exit as the audience is still applauding. He is Skeates, the much-feared theatre critic, who returns to the Daily Post to dictate a blistering review to his secretary Ann. His bad mood worsens thanks to constant interruptions by Tommy, the paper's obituary writer (and Ann's sweetheart) and then by repeated phone calls from an unnamed woman who insists on talking to him. He finally finishes the review by attacking lead actor Edmond Davey and leaves for the night.
Ann finishes typing and is leaving the office when she runs into Barbara Halford, the production's leading lady and Davey's wife. She asks Ann to alter the review to put Davey in a better light, as Skeates' reviews make or break careers. Ann remembers an earlier aside during which he claimed to never read his reviews after dictation - so she rewrites the review acclaiming Davey as a magnificent Othello.
The next day, Skeates is accosted at lunch by a grateful Davey. Skeates storms back to the office and sacks Ann. Ann goes to see Othello, and is spellbound by Davey's performance. Meeting Barbara outside, Ann is invited backstage. Over dinner, somewhat tipsy, she commits a faux pas when she says that her relationship with Tommy was doomed because they were in the same profession and people in that situation can never truly love one another.
Arriving home, Ann finds Tommy sitting on her doorstep, despondent. He hands Ann his latest obituary - of himself, "carried off by a broken heart". Instead of sympathising, Ann breaks into peals of laughter at the discovery that his middle name is Newbiggin, and slams her door in his face. He attempts to woo her by reciting Shakespeare in the street, but wakes the neighbours who pelt him with vegetables.
Ann goes to see Othello every night and visits the Royal Academy to see Davey's portrait. She bumps into Skeats, who admits he was wrong and offers to take her back. Barbara invites Ann to tea, shows her into their flat and then has to pop out briefly. Davey arrives while Ann is waiting, and confesses that he's been smitten by her. He and Ann subsequently meet up in Hyde Park, where Ann is somewhat unnerved by his ardour, especially when he says that he's being "persecuted by jealousy". She tries to leave, but a painter asks her to stay for a moment as she's put the couple in the foreground of the idyllic scene she's been working on.
At home, Ann tries to put Davey out of her mind, but Othello is being broadcast on the radio and all her neighbours appear to be listening to it at full volume. Even going for a walk doesn't help, as car radios are doing the same thing. She goes to Hyde Park in the rain and finds Davey there. Realising that she cannot escape him, she agrees to start an affair with him in a rented Hampstead flat.
The Hyde Park painter attempts to contact Barbara to sell her the now-incriminating painting. Barbara is out, but the painter attempts to bribe her maid Katherine with a percentage. Katherine mutilates the painting to destroy the evidence.
Barbara visits Ann at the office and tells her that Davey is having an affair. She asks Ann to speak to his mistress and persuade her to give him up, revealing that she is pregnant. Shocked, Ann agrees, and writes to Davey breaking everything off. Davey misinterprets the final line of her letter: "You belong to Barbara - as long as she lives" as an excuse to kill her, and resolves to do it onstage during the performance. But Ann, who is watching from the gallery, realises what he's up to, and her screams halt the play. Backstage, Katherine inadvertently reveals Barbara's condition to Davey, and the two are reconciled. Davey and Ann bid each other farewell and the play's producer announces to the audience that for once, Desdemona will survive the evening.
