外星闖入者哈里·范德斯佩格爾和麥卡利斯特將軍擱置分歧，共同面對(duì)更大的生存威脅——即將到來(lái)的灰人入侵。ExtraterrestrialinterloperHarryVanderspeigleandGeneralMcCallisterputasidetheirdifferencesandworktogetherinthefaceofamuchgreaterexistentialthreat-theimpendinginvasionoftheGreys.