Doctor Tyko Glas is a lonely, reserved and introspective man, who is not very fond of other people (including his patients). He is settled in his profession, but has no particular love for it, calling it "the one which suits him least out of all possible trades." Doctor Glas is already over thirty years old, but still unmarried - even more than that, he has "never been with a woman." In fact, the physical aspects of sexual intercourse strike him as rather repulsive. He vaguely desires marriage, but when Miss Mertens, a young woman in town, approaches him pro-actively, he retreats into himself.
Doctor Glas agrees, but the Reverend is not so easily put off. God has given man the task to procreate, and he is only trying to do his Christian duty (no lust or pleasure involved here!). Moreover, there is such a thing as "marital rights..." (for men, not for women, apparently).
Mrs Gregorius again and again visits Doctor Glas and they devise a new and stronger strategy: this time the doctor pretends with the necessary theatricals that he "discovers" that the Rev Gregorius has a weak heart and must abstain from all strenuous effort - especially intercourse - on penalty of suffering a fatal heart attack. This warning works for a time...
Meanwhile, as summer progresses, Doctor Glas has fallen in love with Mrs Gregorius, who is a strong and interesting personality. But there is one problem: he discovers she has a lover, a handsome young businessman, whom she meets for secret trysts. But Glas can't help himself, his love for his patient becomes stronger and stronger, and he becomes a tortured person, as he must keep silent to her about his feelings and knows his love will never be requited...
In his obsession, Dr Glas finally contemplates one further step, something which Mrs Gregorius has never required from him: to poison the minister with a cyanide pill, which will look like a heart attack... He soothes his conscience by telling himself that this would be part of his duty as a doctor, as it would help alleviate his patient Mrs Gregorius' suffering (and it would rid the world of an odious specimen). Glas is obsessed by the idea to free Mrs Gregorius from the oppressive sexual attentions of her husband, and there is a strong element of personal jealousy and rivalry involved here (the odious older man with the beautiful young woman, beast and beauty). At the same time, Glas knows there is no hope, for Mrs Gregorius sees nothing in him, she just treats him like a trusted adviser, but as lovers go, she prefers quite another type of man...
This all leads to a gripping intense ending, but no final resolution: Dr Glas is alone and will remain alone. "Life has passed me by," he concludes.
The novel is not all darkness. Doctor Glas is also a great flaneur who loves to take daily walks through Stockholm, making the water city almost a second protagonist of the novel. Hjalmar Söderberg has given us lively vignettes of life in the great northern city, and among the friends and acquaintances Doctor Glas meets are characters from his earlier novel, Martin Birck's Youth.
"Doctor Glas" is a searing literary masterwork, still completely fresh and vivid, as on the day more than a century ago that it was written.