Greta Zargo and the Death Robots from Outer Space by A F Harrold Greta Zargo is the only person who can save planet Earth from the Death Robots coming to destroy it. Themes If you see then click to see more information for a theme. Please take care as context may contain descriptions of a sensitive nature and/or spoilers. Investigation Being An Orphan BraveryScience FictionHeroismSaving The Earth