The movie opens with a hungover lifeguard, Josh (Xavier Samuel), being woken up by friend and fellow lifeguard Rory (Richard Brancatisano). Rory tells Josh that he shouldn’t have proposed to his sister, Tina (Sharni Vinson), then offers to set a buoy for Josh. Josh visits Tina, who discusses their upcoming move to Singapore. As Rory boards into the ocean to set a buoy, a shark appears and kills a man in the water. Alerted to the danger, Josh quickly takes a jet ski and goes to get Rory, but is too late. Rory is pulled into the water, and Josh is unable to save him before he is devoured.
A year later, Josh now works for a supermarket. While stocking shelves with Naomi (Alice Parkinson) he sees Tina with her new boyfriend Steven (Qi Yuwu), returned from Singapore. At the same time two teenagers, Kyle (Lincoln Lewis) and Heather (Cariba Heine) are parked for a make-out session, accompanied by Heather’s dog, Bully. In the supermarket a young girl, Jaime (Phoebe Tonkin), is caught shoplifting, and temporarily evades the security guard by meeting up with her boyfriend Ryan (Alex Russell), who also works at the store. The store manager, Jessup (Adrian Pang), catches up with her, fires Ryan, and calls the police. The arresting officer, Todd (Martin Sacks), arrives, and is revealed to be Jaime’s dad. After this, Jessup is held at gun point by a robber, Doyle (Julian McMahon). The tense situation eventually escalates, and Doyle’s partner appears and shoots assistant manager Julie (Rhiannon Dannielle Pettett).
At the height of the commotion, a tsunami wave descends on the city and floods the supermarket. Doyle’s partner is killed by the flood, and the survivors injured. As the survivors try to find a way out the security guard is dragged under water. It becomes apparent that a great white shark has been washed into the store by the tsunami. Additionally, a broken wire threatens to electrocute them all. Steven volunteers to shut off the power, and the others dress him in crude armor made of shopping carts and shelves to protect him from the shark. He succeeds but loses his oxygen tube and drowns. Despite their previous conflicts, the survivors work together to get Jessup into a ventilation shaft to go for help. A flood of quarter size[clarification needed] crabs slides out of the vent, startling Jessup and causing him to fall back, however,he manages to grab hold of the vent. Unfortunately, the shark jumps out of the water and eats Jessup.
In the parking garage, Kyle, Heather, and Ryan have been cut off from the others. Ryan helps the couple escape from their drowned car, but a second great white shark is revealed. Kyle ditches the dog, Bully at the last second and they manage to get to temporary safety. After several unsuccessful attempts at luring the shark away, Ryan decides to join them on top of a flipped van, but the shark gives chase. Ryan successfully gets into the flipped van but Kyle falls and is devoured.
Inside the supermarket, the remaining group make a plan to catch their shark so they can swim to safety. Jaime manages to swim to the butcher section and grab a hook with meat to use as bait. The shark does not go for the bait, so fellow survivor, Kirby (Dan Wyllie) grabs a hook and puts it through Naomi’s shirt, using her as bait. Kirby is revealed to be Doyle’s partner, who changed out of his clothes and mask so the others wouldn’t know he was the murderer. Doyle stabs Kirby with a makeshift harpoon, and throws him into the water with the hook. Naomi is pulled from the water as the shark devours Kirby, catching its jaw on the hook and ensnaring itself in the trap. Josh apologizes to Tina, feeling guilt over her brother’s death, but Tina reassures him and kisses him.
Below, Bully is found alive. Heather’s newfound hope inspires Ryan to start banging on the pipes, calling for help. Jaime hears Ryan’ call and with Josh goes to rescue him. Below, they are alerted to the second shark’s presence. Josh and Jaime find her dad’s car, in which are a shotgun and taser. Josh kills the shark with the shotgun, and the four of them get back into the supermarket. A tremor strikes as they are all swimming to the entrance, breaking the first shark loose. Josh kills the shark with the taser as Doyle wires a truck jammed in the entrance to explode, breaking a hole in the debris and freeing them. The survivors leave the supermarket, reaching the severely damaged city, and Tina asks Josh what to do now. At sea, a seagull swoops low over the water, and a shark jumps out and devours it.
‘Bait 3D’ Trailer