Dr. Edward Sanders, an English physician working at a
leprosy hospital, arrives by
river steamer at the port town of Port Matarre in
Cameroon after receiving a summons connected to Dr. Max Clair and Clair’s wife, Suzanne, who run a clinic near Mont Royal in the interior. In Port Matarre, Sanders hears reports that a strange crystallization is spreading through the surrounding forest, transforming vegetation, animals, buildings, and people into rigid, glittering forms. With routes disrupted and the interior increasingly restricted by
military controls and panic, Sanders struggles to arrange transport upriver. In the town he meets Father Balthus, a
Catholic priest returning to his parish, and Ventress, a
Belgian architect whose manner shifts between charm and hostility. Ventress presses Sanders about a pistol that has been smuggled ashore with Sanders’s luggage, and implies that Sanders is being watched or targeted. Sanders also encounters Louise Peret, a French
journalist. Unable to secure ordinary passage to Mont Royal, Sanders and Louise hire a boat and travel upriver toward the reported affected zone. Along the river approaches, Sanders witnesses evidence of the phenomenon, including crystalline growths on a corpse in the water. He learns that the crystallization advances in irregular surges rather than along a stable boundary. Soldiers and officials warn that the forest is dangerous not only because it immobilizes what it touches but because it appears to preserve life in a suspended state. Despite diversions and delays, Sanders continues toward the Clairs’ clinic. With military assistance, Sanders reaches the deserted town of Mont Royal, now hemmed in by forest that has become a luminous lattice of crystal. The transformed landscape is both beautiful and threatening: trees glitter like rigid icons and animals appear frozen into jeweled postures. Sanders is attacked by a sluggish, crystal-encrusted
crocodile and narrowly escapes. Sanders’s journey becomes entangled in a feud between Ventress and Thorensen, the director of a local
diamond mine. The attempt on Ventress’s life is linked to Thorensen’s men, and Sanders is repeatedly used as a decoy or pawn as the rivalry plays out in and around the crystallizing forest. Sanders later encounters Captain Radek, a military doctor he has known, now crystallized and fused into the forest’s outgrowths. Hoping moving water might reverse the process, Sanders frees Radek from the accretions and lowers the body into the river current, which provokes a horrified reaction from Ventress. At Thorensen’s base Sanders meets Serena, Ventress’s wife, who is gravely ill with
tuberculosis. Thorensen claims he is protecting her from Ventress’s instability. He offers Sanders guides to the Clairs’ clinic, but they desert Sanders in the forest. Sanders presses on alone, moving through pockets of normal terrain and corridors of crystallized growth that harden unpredictably. Sanders eventually reaches the leprosy clinic run by Max and Suzanne Clair. The clinic offers temporary safety and a return to routine, but it lies under the forest’s shadow and those around it behave as if drawn toward the crystallization. Louise arrives but chooses to return downriver. Sanders resumes an intimacy with Suzanne, his former lover, and notices she shows early signs of leprosy. Suzanne grows increasingly detached from ordinary fears and speaks as if the crystal forest offers a kind of resolution. Suzanne leaves the clinic and heads toward the forest. Sanders follows her and, exhausted, wakes to find his right arm covered in crystalline spurs. Ventress reappears and forces Sanders to keep moving, insisting that motion delays the crystallization’s spread. The two make their way back toward Thorensen’s summer house, where violence flares again between Thorensen’s men and Ventress. In the chaos, Sanders kills an attacker concealed beneath a crust of crystal and Ventress remains behind to confront Thorensen, urging Sanders to flee. Sanders reaches Father Balthus’s church at the forest’s edge, where an enormous jewel-encrusted
crucifix stands inside. When Sanders holds his crystallized arm near it, the crystal dissolves and his arm is freed. He stays briefly with Balthus as the crystals begin to invade the church. Balthus forces the crucifix into Sanders’s hands and sends him away, remaining behind as the forest closes in. Using the crucifix and scattered jewels to melt or delay crystal growth, Sanders continues through the region. He encounters a trance-like procession of lepers led by a tall hooded figure revealed to be Suzanne. Sanders returns to Thorensen’s summer house, now fully immured in crystal, and finds Thorensen dead and Serena preserved beside him within her shell. Ventress runs past the building, shedding fragments of crystal and crying Serena’s name. Sanders reaches the military perimeter and is seized by troops who accuse him of looting the jeweled crucifix, but Max Clair and Louise intervene to secure his release. Two months later Sanders is back in Port Matarre, physically recovered but unable to resume ordinary life. He settles his affairs at the port, arranges passage upriver, and returns toward the crystallizing interior. ==Themes and analysis==