Scientists studied a dangerous fungus called Calonectria eucalypti that kills eucalyptus trees worldwide. They sequenced the fungus’s entire genetic code and tracked which genes it turned on during infection. They found that the fungus uses different strategies at different stages of infection, starting with penetration, then breaking down plant cell walls, and finally stealing nutrients. This research helps us understand how the fungus works and develop better ways to protect eucalyptus plantations.