Conrad's story explores the moral-psychological dilemma deep-seated in the mind of the Malayan native Arsat. Driven by uncontrollable passion for Diamelen, Arsat, a noble warrior & a sword-bearer of the Rajah, chose to elope Diamelen with the active support of his brother. Possessed with the illusion of a world of love beyond death, Arsat betrayed his own brother who sacrificed his life facilitating the escape of Arsat-Diamelen. When his brother was overpowered by their Ruler's men and he repeatedly shouted for Arsat's help, Arsat was selfish enough to not respond to those calls. As Arsat and Diamelen lived by the side of a weird-looking lagoon in the wilderness, cut off from their social-cultural roots, a strong sense of guilt and moral default steadily ate into their souls. Diamelen fell ill and died untreated, leaving Arsat trapped in a moral darkness in the midst of morning sunshine.
Yes indeed "The Lagoon" is a very complex tale of unrest: unrest born of severe conflicts between love and duty, passion and honour. Love and passion for Diamelen allured Arsat to ignore the summons of duty and honour. Diamelen's death was Arsat's final disillusionment; he could see nothing though there was new light of the rising sun to remove the nocturnal darkness. Arsat fought the wars during the period of community unrest; he fell in love and was restless to mature the same to a domain beyond mortality; he was in deep unrest having lost his brother; he lost his love as well to be plunged into a great unrest of his mind.
The main theme of the story is that death is inescapable, humans often have the illusion that through 'true love' nothing can touch us, and that love makes one whole. In order to succeed in life, one must overcome these illusions.
Man does not contemplate the mortality of life when blinded by youth and courage. The guilt which will inevitably haunt Arat over this unforgivable act betrayal of is veiled by the illusion that love is worth fighting and sacrificing for. Arat, like all men, clung to the illusion of Utopia and “a country where death is forgotten—where death is unknown” (Conrad, 1897) with Diamelen, and later finds that the guilt of his betrayal both to his Rajah and his brother would hang over him like the darkness of the night or the ghosts which the crew believed would perpetually haunt his dwelling. In an insight into the heart of man, Arat states “What did I care who died? I wanted peace in my own heart” (Conrad, 1897). The illusion of peace is an idea which Conrad would be well versed in; a man who led life of torment, who allegedly unsuccessfully tried to commit suicide at a young age, who saw the very animalistic nature of man during his years exploring the uncharted colonies of Great Britain in the Navy and was the victim of a torrid love affair himself.