When there are three cats and six pigeons in the central square at the same time (cannot be artificial), you will receive a hidden mission from President Roland, asking you to go to the final tower to defeat the boss at the end of the level and continue to implant the Trojan virus (the boss behind the scenes). Then you will get the elite difficulty boss of the whole map for half an hour, and the drop rate will be doubled (actually, the president implanted the obtained Trojan virus into the computer, changing the drop rate and elite distribution).

The drop rate of cards and equipment can be doubled, so start swiping it quickly.

According to the actual test, it cannot be triggered below the 34th floor of the climbing tower, and it cannot be triggered if you do not select the story mode.