Jump in the Fire is the 40th level in Serious Sam 2.
Once again, Serious Sam must go through another arena. This one is a time trial/speed run like the first one, but this arena is themed like Planet Kleer. The usual checkpoints are scattered throughout the arena, and there are enemies scattered throughout the area.
When Sam completes the arena, the area is attacked by the Alliance, who found a way to get past Sirius' shield and attack Sirius with all their strength. An Alliance ship lands in the arena, picks up Sam, then starts heading towards Mental's hideout.
There are no secrets in this level.
The name of this level is a reference to the eponymous song by Metallica.