trouble on the horizon. 麻烦出现了

99. The challenge is catching them.
    难点在于如何捕捉
100. Finally.
     终于吃到了
101. But just when it thinks it's cracked it,
     但就在它以为问题已经解决时
102. trouble on the horizon.
     麻烦出现了
103. These prime fly-catching spots are in high demand...
     理想的捕蝇地点很受欢迎
104. ...and the locals do not like to share.
     当地居民不喜欢分享
105. A stalemate,
     双方僵持不下

来自《我们星球上的生命 第一季 第四集 Life on Our Planet S01E04 冷血动物》第 102 行