1. Begin a two player inferno game.
2. Progress through the quest normally until the near end is reached.
3. Player one stop participating.
4. Player two attempt to progress through the level.
Result: In higher difficulties, the player will have a hard time progressing due to the extra difficulty brought upon by the existence of the idle second player.
If the duo is in the middle of a long quest and one player decides to no longer participate, the other player will have no choice but to leave and lose quest progress.
Expected result: The player is able to progress through to the next quest without dire consequences regardless of his partners participation.