What wonderful story does "Darkest Hour" tell?

Sean and Ben are two software engineers from the United States. Because they developed a new software, they went to Moscow to discuss business. They went to the bar to have fun at night and met Natalie who came from the United States to travel. (Olivia Thirlby) and Ann (Rachael Taylor), the four of them were flirting and having fun, but they encountered a white light falling from the sky and a catastrophe on the earth. They turned out to be aliens in the form of energy fields. Invading Moscow can destroy any living thing in the moment of contact. Four young Americans hid in time and tried to escape from the desolate Red Square when night fell. They discovered that electricity could sense the presence of aliens and found an old geek who had installed an electromagnetic array in his home.

Everyone works together to try to find all the survivors, and use the knowledge of electromagnetism to fight back against the aliens?