Fresh from training, Varadhan Annadurai steps into his first assignment as a Sub-Inspector, handed an old, unsolved murder from the honeymoon days of a young couple in Ooty. He is paired with the diligent Pavithra, and together they reopen the case file, combing through the missing jewelry, the reports of robberies with a similar MO, and the memories of witnesses who were there sixteen years ago. The mission begins with a careful recheck of the trail: Varadhan interviews the officer who handled the original investigation, cross-references police records across the state, and follows a thread that leads him to a potential match in Coimbatore, sparked by a batchmate’s tip about a related theft in Kumbakonam. The pursuit quickly becomes a race against time as a carjacking incident resurfaces, pulling Varadhan and Pavithra into a tense chase that sends them deep into the night along treacherous ghats.
As the midnight hours unfold, a bus from Ooty embarks on a fateful journey toward Coimbatore. The passengers include a pair of lovers fleeing a powerful MLA father and a fragile, jewel-laden world of danger and desperation. The lovers’ tale adds a personal stake to the danger: Gunasekaran, a local bully and politician, is determined to erase any obstacle to their union and to reclaim the stolen jewels. A troupe of tribal riders also boards the bus, and a broader cast of families and travelers adds texture to the peril aboard. On the move, the robbers eye the loot, while a growing sense of dread settles over the passengers as unnerving whispers of fate and fate’s hauntings begin to creep in. The bus becomes a moving stage for fear, with a young man and an older woman sensing something otherworldly as they approach a pivotal stop at a temple, where a plan to safeguard the lovers unfolds before them.
Varadhan, following the trail from behind the bus, finally corners the carjacker Satya and retrieves his stolen weapon, but the revelations do not stop there. A string of eerie signs soon makes him question reality: the IDs of the conductor and driver surface, the bus number checks out, and Pavithra’s background checks reveal a deeper mystery. The raid at hotels near the murder site uncovers nothing tangible—until Pavithra discovers a chilling twist: the bus that vanished sixteen years earlier vanished again, with a bus number that doesn’t exist on any current timetable. The tension escalates as Gunasekaran’s henchmen close in, eliminating witnesses and pursuing the same jewel-laden fugitives. The confrontation reaches a crescendo when the bus careens off a gorge at the infamous 13th hairpin bend, leaving only a handful of survivors.
In the wake of the crash, Varadhan and Pavithra uncover a shocking truth: the wreckage they locate is not the present-day disaster but the long-buried remains of the original tragedy—an ancient bus whose passengers perished sixteen years ago. Varadhan infers that the bus he boarded was a supernatural replica that carries the dead aboard as ghosts, and the honeymoon murder the robbers committed long ago is the same case he is actively solving. The ghosts, bound to their fatal route, continue their journey every time the clock nudges the 13th bend, and the eerie Bus 375 urban legend explains why the living cannot always find the truth. With this revelation, the pair connects the past to the present, confirming that the missing bus’s number plate and the conductor’s credentials match the old records. The couple’s killer is brought to justice through circumstantial evidence, and Gunasekaran is finally arrested.
In the epilogue, Varadhan’s past returns to the foreground as he visits the priest who raised him at the foster home. He learns that the car from the prologue—the one involved in the fatal accident at the 13th bend—was driven by his father, with his mother aboard; their deaths left him in the care of the priest. Four years later, Varadhan has built a life with [Pavithra], and they reflect on the haunting truth: the leap-year coincidence ties their fate to the curse of the bus. The couple discovers that the haunted journey repeats every four years on February 29, and one midnight, the bus appears again at the stand. The scene closes with Satya boarding the spectral bus to reunite with his mother, a final, haunting reminder that some stories travel beyond the confines of the living world.
