Ooh, I've had a nastier thought - you could "Stone Tape" them! (Look up Wikipedia for the one-shot TV show.) Creepiest thing I've ever seen - Ok so it was 1974 & I was young & impressionable, but I've never forgotten it.
The psychic impression is stored on the "stone tape", masking the original recording from hundreds of thousands of years ago. The recording, 'natch, engages all the senses (being psionic), and can even be perceived by psi-shielded individuals (although you may allow them to be more in control of their perceptions). Feel free to throw in images of whatever Lovecraftian eldrich horrors, Primordials, Ancients, whomever you want - although the disembodied lights (eyes?) that ever pursued the heroine were worse, in many ways, because they left it to your imagination as to what she eventually saw...
Sorry, I know this is a reverse-Scooby, but I think if it could be played well it could be pretty cool...