Mighty follows the story of three ordinary friends, Ellie, Isaac and Anthony, who work in the IT Department of a powerful and enigmatic corporation. One day, the entire department is fired without notice and under mysterious circumstances. In their haste to vacate the building, the department head David leaves something behind in his office. He doesn't say what it is but lets slip that it is something very important to him. Fiercely loyal to him, the three friends impulsively cook up a crazy plan to break back into the building even though they have no idea how they will get past security and don't know what they're looking for. After a series of mishaps, they somehow manage to get into David's office but what they find reveals a dangerous secret behind their company that unravels the conspiracy behind their mysterious dismissal. Plunged into a situation far more treacherous than they had anticipated, the three now need to break back out while keeping both their lives and the secret safe.
Mighty is inspired by the exploits of David's Mighty Men, in particular, the small elite group known as The Three. In this biblical story, David, while exiled and in hiding, expresses a wish for the water from the well of Bethlehem. Bethlehem was behind enemy lines but his three most loyal men, upon overhearing David, impulsively decide that they must fulfil his desire. Likewise, David in Mighty doesn't command Ellie, Isaac and Anthony to help him but they do so out of impetuous love and loyalty. The Three risk their lives to break into the fortified enemy camp, steal water from the well, and then fight their way back out again. Despite being seasoned fighters, the odds were heavily against them, like how the odds were against the three friends when they decided to take on a whole Corporation. Eventually, both The Three and the three friends encounter a different result from what they had expected, as David in the bible pours away the water in respect for his men's sacrifice and Ellie, Isaac and Anthony find something completely unexpectedly.