On New York's Liberty Island a massive fireball crash lands, with a man emerging unscathed. He's Dave, a human-shaped spaceship controlled by 100 aliens, each one an inch tall. Its captain (also played by Murphy) pilots the Dave Spaceship along with his crew from inside its head. The aliens are seeking a way to save their planet, Nil, from an energy crisis by draining the Earth's Oceans for salt. However, complications arise when the Captain falls in love with single mother Gina Morrison (Elizabeth Banks). More complications arise when the police begin tracking Dave from the crash site. While the Captain struggles to keep their identity hidden, his best friend, Commander Number 3 (Gabrielle Union) is secretly in love with him and becomes jealous of Gina. Now he must choose between Gina or his true love within Number 3.