外星闯入者哈里·范德斯佩格尔和麦卡利斯特将军搁置分歧，共同面对更大的生存威胁——即将到来的灰人入侵。ExtraterrestrialinterloperHarryVanderspeigleandGeneralMcCallisterputasidetheirdifferencesandworktogetherinthefaceofamuchgreaterexistentialthreat-theimpendinginvasionoftheGreys.