Game crashed

Put the summary of the bug you're having here

What I expected to happen was...:
the game effectively and efficiently load the netherworld

What actually happened was...:
entering/leaving netherworld taxed my system to the max

Steps to Reproduce:
1. Enter Netherworld portal.
2. Wait...
3. Wait...
4. Eventually, play a bit.
5. Leave Netherworld.
6. Wait...
etc.