Space debris falls from the sky and begins to infect people by controlling them . Where have I seen that plot before ? let me see now THE PUPPET MASTERS , THE BLOB , THE THING , the first three QUATERMASS serials , INVASION OF THE BODY SNATCHERS and umpteen DOCTOR WHO stories . It`s impossible not to be reminded of these stories while watching INVASION . It`s also impossible not to be reminded that they all did the same story a whole lot better than INVASION did also