In order to catch the pirates, 2 companies were loaded into a trirem that was disguised as a merchantmen. Since a caravan was being created at the moment, it was hoped the pirate wouldn't get the trick. The plan was for the men to hide in the hold while the trirem would follow a course toward the Foul Empire. A few dozens miles out of port, the sailors would commit some kind of mistake, ripping off a sail (replacement is planned) and further enticing the pirate to attack. When they attack, the men would come out, using surprise to overcome any resistance.
As well as those two companies, the ship will also transport Bran the Cunning, the Minister for Trade and Industry, who'll made the following annoucment:
"Men of the Seas! The Emperor, may he be blessed, knows of your plight. He knows that the riches brought to Brent by the merchantmen end up in a few privileged pocket, and that few opportunities exist for the youths of Soutern Brent. He knows that most of you only want a comfortable life. And He's offering you this.
Face it, Piracy isn't what you thought. Being a pirate means risking your life for some loot and living in fear, hunted like a rat. Instead, the Emperor is offering you to become his Imperial Coastal Guards. Rather than having to fight and kill the merchants, you'll be given money from them without a move, as taxes. And rather than living like a rat, always fearful of the Empire's constable, you'll be respected and like a live of ease!
Remember, there is always two path for men in the Empire. You can go the way of the McKarmon and become faitful vassal of the Empire. Or you can go the way of Brian The Fool and live a life of misery, bringing eternal pains to your family, your friends and yourself. Both the Emperor's generosity and His wrath are infinite, and the choice between the two is yours to make."
...
Or So was the plan. When the time came for Bran to get into the Trirem, not a single men was there. The boat captain himself was not sure whether he was to help invade Aelstrom or stay here. And of course, nobody had though of alerting Bran. Surely not that arrogant Bearskin, that understood nothing to diplomacy...