Countries are special. Routes built into them are dead ends.
Tickets might connect a city to a certain country (self explanatory), or it could be a Country-Country or City-Country ticket. These tickets show a start point (a city or a specific country) and then show all the other countries with scores next to them. If you connect to one of those countries, you get the points on that card. If you connect to multiple countries, you get the one with the highest score. If you don't connect any, you lose the smallest amount of points.