It's clear from trailer that Mulder has a new informant. Whoever this old man may be, he knows more than he is telling. Mulder states in the trailer, in a dialogue snippet with him, that "You said that if I ever put the pieces together, you would confirm." Eventually, this mysterious man comes back with "You're nearly there. You're close." Close to what isn't fully explained, but one would imagine it involves, again, colonization. It should also be noted that one of the clips leading up to this scene appears to be from an early X-Files episode, of Mulder in a warehouse, witnessing a UFO taking flight through the windows (the Operation Paper Clip storyline). Is this a one-off character, or a new Deep Throat/X style informant? That remains to be seen.