It happens often: you’re running around with your portal gun, holding onto the companion cube for dear life while hundreds of rounds of bullets bounce off your friend as he protects you. You see your destination and realize there’s a half dozen turrets pointed in that direction. You sprint forward and accidentally throw your companion cube, or drop it. GAME OVER. But the beauty of having the companion cube is that it’s tough, it’s durable and it’s always there with you, even after a test gone horribly wrong.