Mercenary Mode is a game mode of Just Cause 2 that is unlocked after completing the main story.Game Summary pops up after the mission "A Just Cause" ends.
During mercenary mode the unlock bars (Next faction mission; Next Agency mission; Next stronghold takeover and Next Black market unlock) are replaced with the word COMPLETION and a total percentage.
All faction and stronghold missions that were not completed before the final agency mission will still be available.
There is often a glitch which makes all civillians / cars disappear. To fix this, start and finish any race and it will bring everyone back. See also:Just Cause 2 Patch and Bugs.