Round 1
In an explosion of movement, the party attacks.
Karnage strikes out swiftly but his sword clangs off his opponent's robe.
Bertrem lashes out with his mace and crushes his opponent's skull. He goes down, splattering blood and brains.
Si'Nat's arrow takes a second one right in the upper chest, near the shoulder. He staggers back but remains standing.
Patrick's dagger takes the third in the eye.
Rondo's blow and Cugel's arrow misses the remaining, wounded creature.
Round 2
The creature turns and starts to run back down the stairs. You guys get a "free" attack (+2 to hit rolls).
Karnage misses horribly, but Bertrem steps up again and smashes his mace into the back of the creature's head. Its momentum carries him down the stairs, tumbling and bumping until it reaches the bottom, unmoving.
(I gotta say, I rolled incredibly for you guys this time. Except for the misses, everything was 15 & above, which with the bonuses each gets for attacking (depending on who it was), got you guys hits...)