Hi there,
for one of the next adventures, I am planning that a mad scientist has recreated the Nanogene spore . He lives in a hidden lab on a forest/jungle planet. His version of the virus will also infest the flora, not just the fauna. The transmission will be only by skin contact, however, the virus turns the organic matter of this victims into a fear gas during the transmutation, which petrifies new victims and a host can touch them to spred the virus.
The result looks like a chromed forest full of dire mecha-zombie-creatures and -people, which is veiled in clouds of yellow fear gas.
How would you solve this rules-wise?