Complex sentence: When Will gets out to check him, Martin's phone starts ringing and the sniper, Gorman, starts shooting at Will, who grabs the phone, leaves the car, and is chased through Madrid by police and by Gorman.
Split into simpler sentences: When Will gets out to check him, Martin's phone starts ringing and the sniper, Gorman, starts shooting at him. He grabs the phone, leaves the car, and is chased through Madrid by police and by Gorman.