This story is a work of fiction with AI illustrations. Its characters and discoveries are imaginary.
This work of fiction follows the expedition of Arunika, a research vessel searching for the source of a mysterious sound in the Serandil Trench. On a moonless night, its radio picks up a fragmented message from Samudra Jaya, a survey ship declared missing twenty years earlier.
A call from the depths
Captain Mira ordered Banu, the radio technician, to play the recording again. Through the static came a woman's voice: ‘Trapped in the control room. Oxygen running low. Follow the three strikes.’ The coordinates accompanying the message were eleven kilometres from the expedition's route. Strangely, the signal used Samudra Jaya's call sign, complete with a typing error recorded in the ship's final archives.
Arunika changed course. Sonar soon detected a long shape wedged in a gap between underwater cliffs. Three metallic strikes echoed every sixty seconds, too regularly to be dismissed as the sound of currents. Mira, Banu, and diving specialist Dara descended in the mini-submersible Niskala. Its lights swept across a rusting hull bearing the name SAMUDRA JAYA. From the stern, a new cable stretched towards a dark cave.
A control room still alive
They followed the cable and found a small pressure module secured inside the cave. A green light blinked on its door. After they entered the emergency code, the door opened and an elderly woman fell into Dara's arms. Her name was Lestari, Samudra Jaya's sonar operator. She had not been trapped for twenty years; she had secretly returned three weeks earlier to finish searching for her older brother, the ship's captain, who had disappeared with the other crew members.
Lestari explained that she had found the voyage recorder in the wreck, but a landslide had blocked her way back and damaged her transmitter. The message Arunika received was an old emergency recording that she had combined with new coordinates. The three strikes came from an automatic hammer she had fitted to the module's wall. Now the backup battery was nearly exhausted, while cracks in the cave kept widening.
Racing the landslide
As they prepared to leave, a small earthquake shook the cliff. Rocks blocked the route Niskala had taken. Dara spotted a narrow gap above the wreck of Samudra Jaya, but the submersible could not fit through while carrying Lestari's module. Mira made a risky decision: abandon the module, move Lestari into the submersible, and use the mechanical arm to push away the debris piece by piece.
Oxygen dwindled as the submersible's engines fought the muddy current. Banu activated the hammer signalling device and changed its rhythm to guide Arunika on the surface. The ship's team replied through sonar, indicating an alternative passage. A few metres from the exit, a large rock fell and trapped one of Niskala's landing legs. Mira released the leg using the emergency bolts. The submersible tilted sharply but finally escaped the cave and began to rise.
An answer to the final message
On Arunika's deck, the medical team stabilized Lestari. The voyage recorder she had brought back was intact. Its contents revealed that Samudra Jaya had sunk after an underwater landslide damaged its hull, not because of a mutiny or a mysterious creature, as rumours had suggested. The captain's final recording stated that all crew members had tried to reach the lifeboats, but a storm had prevented rescue.
Several days later, the wreck's location was reported to the crew members' families and the maritime authorities. Lestari handed over the recorder, then admitted to her secret expedition so that no one else would follow the same dangerous path. The signal stopped because the module in the cave had been destroyed by the landslide. The mystery was resolved: the call was not a ghost's voice, but a younger sister's final attempt to discover the truth and bring it home.