The game is a spiritual successor to [i]Left 4 Dead[/i]. The scene in question has the players fight through zombies to cross a bridge to only be told they have to go back and plant bombs on said bridge to keep the zombies (or "Ridden" as this game calls them) from following you. UI couldn't find any of those guys handing over bombs and assumed they were auto-added to my inventory, so I went to the couple different spots that I am supposed to plant a bomb but can't figure out how to do it