Describe how Thorbjorn Sigurgeirsson and Sveinn Eiriksson work together to fight against the lava that threatens Heimaey's town and harbor.

Thorbjorn Sigurgeirsson is the brains behind the lava cooling operation in Heimaey. He is a scientist who comes up with ideas to cool the lava. Sveinn Eiriksson is the person who executes the plan. He is a fire chief and skillful commander who takes Thorbjorn's ideas and puts them into action. Together they make an effective team.