<l:1,93>Chem Troopers<e>, <l:1,53>Infectors<e>, <l:1,95>ABC Clones<e> and <l:1,58>Aquatoids<e> can infect a city with a plague, which causes 5 <l:6,96>unhappiness<e>. Any <l:6,104>city<e> trading with the infected city has a 30% chance of becoming infected in the next turn. However, if the attack fails the perpetrator is surely caught. The attack costs 1,000 <l:6,92>gold<e>.