Meanwhile in the tunnel, your surprise attack rips through your opponents.
Dyria moves to a better position, and finds she still has time to slash the wounded rat in half on the way (only needed a move action, so she got an attack)
Murdoch sends a cone of acid over one of the barricades, burning the two rats behind.
Barnak basts five darts of force from his hand, blasting five smoking holes in the wizard's back. He falls.
Alethia activates her mighty laugh as desribed, and begins glowing.
The archons miss.
Two of Marco's men fire arrows at the rats from the top of the shaft, still writhing in pain from the nearly-fatal (and ultimately, it would have been fatal on its own) acid burns, killing them.
Marco himself dives down the shaft, driving one knife into a warrior's jugular, and holding on. (50dmg)
The rats manage to get their shots off before you do. Murdoch and Dyria are too strongly protected by steel and force fields, and of the six arrows fired in their direction, five are either wrap around the force fields and miss or clank off their armor. Dyria is surprised when one penetrates her (crit, 30 dmg).
The six fired at Alethia and Barnak all hit (ten points of AC make a world of difference). One of Alethia's crits (39 dmg to Alethia, 32 to Barnak).
The three nearest rats drop their bows, draw swords, and charge towards Barnak, Murdoch, and Alethia. All strike true (21, 24, and 26 dmg respectively)
Dyria tries her Death Spiral Technique for the first time since capturing the master of war within her ring gauntlet. The whip divides into a dozen different long, writhing, barbed tenticles. She can strike both warriors and five rats. All are struck hard, and stumble, nearly falling (all are stunned 3 rounds and take 24 dmg).
Marco's falls under the smuggler's weight, and Marco drives his other blade into the warrior's face several times, killing him.
Alethia charges and strikes the other stunned warrior accross the head with her mace (20dmg)
Murdoch hurls acid at the three rats with swords (31dmg, 16 to the rest). The one in fron of him falls dead with a gaping acid hole in his chest. Barnak sees no spellcasters so blasts the rat that just stabbed him instead (32dmg), leaving the rat in a dead smoking heap.
Kayla slides down the chain shaft, jumps, runs a few steps and jumps on the rat that stabbed Alethia, slitting his throat.
Marco's two archers shift position and shoot at the other two stunned rats (18 dmg each). Marco's two remaining soldiers slide down the shaft, and charge those same two rats, striking their heads from over the barricade. Both fall dead.
Four rats and the stunned warrior are still standing.