That Special Someone

U.L. Paper will give you a call to tell you that Darko Brevic has entered Liberty City.

Call Roman and pick him up.

When you get to the airport, watch the cutscene and then choose to let Darko live or die.

The choices don't really matter, the outcome is just a change of dialogue.

When you beat this mission on the Xbox 360 verison you get the achievement that special someone and get 10 gamer points.