the Crates: The central barrel contains a Healing drop!
Bring your groups to meet in the middle by the barrel, then place a
character in the gap created to hold the route open for your characters
to run through. It should be possible to get Dantares or Masqurin through
if you're lucky, but it shouldn't take any longer than three turns to
get someone through the crates and out on the other side.
Once you're there, talk to Irene and she'll join your squad. Just make
sure she doesn't get killed or you'll lose her and have to start again!
Fight off the rest of the enemies - the battle ends when only the birdman
on the crates is left standing.
If you save Irene and then retreat from the battle she will no longer
be in your team, you must talk to her and go on to win the battle to
secure her permenantly.