Monster, hero, Guardian: Groot! Before he was a Guardian of the Galaxy - before the Grootfall - young Groot lived a life of tranquility on his serene homeworld, Planet X. But when monstrous invaders attack his world, this courageous sapling must shoulder a heroic destiny! And this destiny will lead Groot to cross paths with a young Kree soldier by the name of Mar-Vell! But who - or what - is behind the devastation of Planet X? Does any life yet stir in its decimated forests?