20th Century Fox has pre-emptively bought Mark Burton's spec They Came From Upstairs. Sources peg the sale at $1.75 million against $2.25 million, says The Hollywood Reporter.

The high-concept adventure tale is described as Home Alone meets Gremlins. Upstairs originally went out as a pitch, drawing interest from several studios. But Burton, whose credits include Madagascar and Wallace & Gromit: The Curse of the Were-Rabbit, pulled the project off the market, opting to write the screenplay himself.