The Imperial Guard's Orders is a tome found in Act II of Diablo III, found in the Rotting Cellar below the Dahlgur Oasis. It is dropped after killing some Imperial Guards who are tormenting Javad the Merchant.
This tome is required for the Judge of Character achievement.
The parts read as follows:
The enemy has destroyed Alcarnus and most of the cultists. The master commands us to capture more slaves immediately. Go to the oasis and abduct the villagers. Kill any who resist. That way, we shall both gain allies and destroy enemies. — Captain of the Imperial Guard