They ran into a semi-recurring background character (potential villain?) that had generally looked tough at them.
I described him as a ghostly orc in fantasy/steampunk space marine armour.
Orc of Moria Swordwraith Mechanus Warrior 4 (Dark Minded, Unliving)
HD 4d12+12 (38hp), 'Large' size (Huge for numbers)
AC 26 (+16 armor), 25% Fortification, DR 10/epic, Sv +7/+1/+2 (Fort vs illusion), Immune Poison
Weapon Cogs +15
Diamond Drill 2d6+4/x4, ignore DR/Hardness
Magnet Dust Drill 1d8+11, touch
Rotary Drill 2d6+11/x4
Gear Thrower 1d6+2/18-20, 60' increment, double
Special: Locate Object 1/day
Stats 24, 10, 16, 6, 12, 10
Feats: Track, Endurance, Combat School, Juggernaut
Skills: Linguistics +5, Stealth +9, Notice +8
Gear: Mechanus Armor (Revising Tome Armor thread version), Tower Shield
Orc of Moria Swordwraith Mechanus Warrior 4 (Dark Minded, Unliving)
HD 4d12+12 (38hp), 'Large' size (Huge for numbers)
AC 26 (+16 armor), 25% Fortification, DR 10/epic, Sv +7/+1/+2 (Fort vs illusion), Immune Poison
Weapon Cogs +15
Diamond Drill 2d6+4/x4, ignore DR/Hardness
Magnet Dust Drill 1d8+11, touch
Rotary Drill 2d6+11/x4
Gear Thrower 1d6+2/18-20, 60' increment, double
Special: Locate Object 1/day
Stats 24, 10, 16, 6, 12, 10
Feats: Track, Endurance, Combat School, Juggernaut
Skills: Linguistics +5, Stealth +9, Notice +8
Gear: Mechanus Armor (Revising Tome Armor thread version), Tower Shield
The fire mage in the group was also killed, and the rest of the group escaped with their lives. The player, after lots of checking, is fine with the loss and is looking forward to making a new character.
Holy crap, I didn't expect that to happen. I don't know whether to have the orc and his entire group level up from that fight (none of them died). The rest of the party levelled up already because they finished their quest afterwards (I do quest-based advancement, not fight-based). Suffice it to say, my party is going to be VERY cautious around the orc and his group from here on out.