Although he had found the trace, Ling Feng did not strike because he understood that an assassin of the airport's caliber simply could not undertake a fifty million US Dollar job!
According to the rules of the underground assassins organization, to undertake a fifty million US Dollar task, the assassin's strength should at least be at the silver level! However, the strength of that airport assassin was, at most, black iron level! And black iron is the lowest existence among assassin ranks!
Above black iron is brass, then comes silver, gold, and diamond! Of course, even if a Silver Assassin were here, he would likely not be a match for Ling Feng!
If this incident had nothing to do with Bai Feifei, Ling Feng couldn't care less about such trivial matters!