Warner Bros. has snapped up a sci-fi spec script dubbed “Expulsion” by mystery writer Gregg Hurwitz and set it up with Brad Weston.

Story centers on a small band of survivors escaping to a planet beyond the solar system after a terrorist attack destroys Earth.

Double Nickel Prods. acquired “The Legacy,” a spec from Hurwitz earlier this year with Jenette Kahn and Adam Richman at Double Nickel set to produce (Daily Variety, June 25). “Legacy” is a drama wrapped around a perfect crime centering on a mother in her 30s and her two amazing boys.

Hurwitz’s mystery titles include “The Tower,” “Minutes to Burn,” “Do No Harm” and “The Kill Clause.”

His latest, “They’re Watching,” has been optioned to Big Kid Pictures for David Dobkin and Jeff Kleeman.