Running OSX 10.7.4 with Steam client fully updated. Episodes 1 and 2 worked fine, as soon as I downloaded episode 3 I can no longer access the game. All I get is a black screen and my computer becomes unresponsive.
At this point I have already tried deleting and re-downloading, waited with the screen black for over an hour, have verified the integrity of the game cache multiple times, and have tried deleting my save files to no avail. Any help TTG?