Complex sentence: Baruchel is uncomfortable at the crowded party, so Rogen accompanies him to a convenience store for cigarettes, but beams of blue light came down and sucked numerous people into the sky.
Split into simpler sentences: Baruchel is uncomfortable at the crowded party, so Rogen accompanies him to a convenience store for cigarettes. There, beams of blue light come down and suck numerous people into the sky.