Forum:Point lookout mystery helper

i noticed at random times in point lookout i will receive 'help' in the form of rifle shots while engaged with enemies. it is definitely not mysterious stranger, as it happens in or out of VATS and is not an auto-kill. additionally, there is the sound of a bell after the battle is complete when i receive this 'help'. the source of the gunfire always seems to be from a great distance and no one ever shows up on radar in the direction of the shots. what the hell is this?