How does this work ? That is, if it actually does . . There was an AI city which had my culture on three sides. Their culture was falling by a steady 1% per turn, and was down to 32% when I launched my spaceship. They having nothing better to do, I sent my spies to spread my culture into the city, by a stated 5% a time and at trivial cost.The AI culture still fell by a steady 1% per turn (except for one turn when it didn't fall at all) despite 23 successful "spreads" during my ship's flight, so the spy activity had no effect whatsoever. During that time, the city's garrison remained at 2 longbowmen and it completed no buildings.