Quick background: I currently have a level 6 alchemist of my own (I pretty much only play at conventions) as well as a level 2 dummy from GMing for a group of friends. This group has not really played together very much, but all of them are RPG veterans and have played multiple systems. I wouldn't say they are power gaming monkeys, but they do make effective characters. They are all new to Pathfinder though they have experience with D&D. I am running a CORE campaign, and this is a list of the sessions we have done so far:
1) Master of the Fallen Fortress
2) First Steps Part I: In Service to Lore
3) The Confirmation
4) The Devil We Know Part I: Shipyard Rats
Tomorrow's game:
5) The Devil We Know Part II: Cassomir's Locker
Keep in mind that there are only four PCs: a ranger; a rogue; a cleric and a wizard. They use solid tactics and built good, effective characters. That being said, they have utterly facerolled through every adventure. Only in 2-3 fights has one character fell unconscious, and I think one of those times two characters were down. I understand that the adventure content should not be altered at all, so I feel pretty powerless as far as posing a credible challenge to the group. I don't want every single encounter to be death-defying obviously, but I also don't think they should be ROFLstomping every one either.
Any suggestions? Is there anything I can actually do to increase the suspense or thrill of the game in terms of danger, or are all PFS scenarios this easy? Again, I've only really played 15 scenarios so far on my Alchemist, and the only difficult ones were when we played up a tier (save one--Silver Mount Collection but that was largely due to party dysfunction).
I'd appreciate any feedback.