Season 4 Episode 11 - Point of No Return

The SGC is contacted by a rambling individual who claims full knowledge of a host of government conspiracies, from the Kennedy cover-up to CIA-sanctioned microwave harassment of Libertarian candidates. He sounds like a crackpot, someone hardly worthy of their attention, that is until he mentions the Stargate. O'Neill meets with the mystery caller, Martin Lloyd who insists he is an alien and in possession of a space ship (who's location slips his mind at the moment). O'Neill is ready to dismiss Martin as a harmless nutjob and head back to Cheyenne Mountain, however, a series of strange occurrences begin to suggest that maybe, just maybe, there could be some truth to his story.