

You need to take prisoner any Swedish unit - easiest way is to intercept a small patrolling party and kill one of them with a blunt weapon like mace (don't forget that horses and firearms in melee also deal blunt damage). King Jan Kasimir will ask you to capture a Swedish soldier. When the King reads it, you will find out that the letter warns of a Swedish invasion.Any Polish lord when asked will give you a letter to be delivered to King Jan Kasimir.Talk to Zagloba and he will advise you to find any Polish lord and ask him for a special mission. Find Colonel Zagloba and invite him to your party.Ask Polish lords "Perhaps you can tell me of a way to help the Polish Commonwealth?" until one tells you to make friends with Colonel Zagloba, who must be in a tavern.You must accept if you wish to start the main quest. He tells you that Poland is in danger and asks your help. Ask a Polish lord "Tell me - what news have we from the Polish Commonwealth?".Achieve at least +10 relations with Poland.
