Send Spy

Send Spy gathers military intelligence on an enemy. It reveals their regions, troops, defenses, gold, and more, so you can plan an attack. If the mission fails, your spy is caught and does not return.

No operation succeeds more often, whoever you send it against. The Covert Operations topic explains the odds.

Send Spy answers on the spot. It is one of the few operations that does not wait for daily maintenance, which is what makes it useful right before an attack.