Here is the situation:
Two conjurors, one a human the other a centaur, have just opened a door in a dungeon controlled by a mad and powerful goblin wizard. They look out on a cavern - 50 metres to both right and left, 150 metres across to another door, the 'floor' a lake of lava. High above (100 metres) is a rope bridge upon which are some 30 goblins. There is a ladder to their left that goes up to the bridge, across the cavern is another ladder going from the door to the bridge.
The human can do all conjuring spells from L1 to L4; she speaks Goblin. The centuar can onlyu cast L1 and 2 conjuring spells; she has a 2d6 bow.
The pair need to go on - there is no way back now. What could they do to get across and pass through the door on the other side?