Cursing, Soval shouts back to the group in his strongest voice.
"The advance party is under attack! TO ARMS!"
As soon as anyone nearby arrives (some of his henchmen scouting with him, perhaps?) he will station one or more at the entrance, preferably with spears or pole arms. "If you hear the battle cry," he says, "pour in. But we can't block the narrow tunnel, or we may get the poor sods killed on their retreat. So wait here and attack anything not man, elf, hobbit, or dwarf that comes out."
Then he takes one or two (PCs and/or his own henchmen) with him into the tunnel, to scout things out and join the fight.
IF there is no-one nearby and he gets no response, he will move cautiously into the tunnel, calling ahead. IF only one person shows up, he will send that person for help with the guard-the-tunnel-mouth instructions.
IF he encounters PCs fleeing on the path (looks like a couple of the elves are booking already) he will help them out and press forward right away, not worrying about the others, hoping to cover the wounded in their retreat. "How many are left?" "Are you allright?" "Cover the gate incase they break out after us!" type questions to the surviving PCs from below as they come.
the Elf Medium (MV 12", AC 9, HD 1, hp 1/1, AL N) great cloak, lantern
; spells: color spray; scrolls: sleep, sleep, charm person
Hirelings: Georges; torch