During the game's finale, Roman attempts to persuade Niko into striking a drug deal with Dimitri Rascalov due to the amount of money involved.
Niko vows to track down the culprit, motivated not solely by revenge, but a need for closure and to move on with his own life.
Niko is criticized by many of his friends and (most notably) by Roman for this weakness.
His first girlfriend was Michelle, whom he later leaves after she turns out to be an undercover detective, and his later girlfriend, Kate Mc Reary either dies at the end (if the player chooses Revenge) or feels disappointed in Niko for violating his principles, but forgives and consoles him in his time of loss (in Deal).
For the first time in the series, Grand Theft Auto IV features "morality choices" in several points of the game, in which the player is forced to choose between killing or sparing a character, or killing one of two characters.
In some of these situations the player can choose to carry out execution-style killings, which are played out as cut scenes.