At the end of each of the Miner’s turns, the Bacteria attack!
To determine which type of Bacteria will attack, look at the Stomach card closest to the Miner. The type of the Bacteria depicted on that card will be the one that will attack the Miner this turn.
Increase the Bacteria level by moving the corresponding Bacteria tile one space along that track towards the Miner. The tracks on the Beast’s board represent the infection level for each type of Bacteria.
If this results in any one Bacteria tile reaching the 4th level, the game is over and the Beast has won.
Then discard the Stomach card, sliding the other Stomach cards towards the Miner to fill the empty space.
Finally, reveal the Beast’s Mutation card (except in the first turn), and apply its effects.