Scouting, Spying and Scrying

[thejeff]

Spies have two uses. First, they're better scouts. They give more accurate reports, including PD strength.
Second, they can cause unrest in enemy provinces. This is reported to the enemy, so it's risky, but can shutdown a crucial province at the right moment.

Astral Window & Astral Projection are the only two I know of. I believe these give the same level of info as a spy.

The relevant thing about glamour units is that they can't be seen on the overland map. Not in neighboring provinces or by scouts, spies or scrying. (I'm assuming on the scrying.)