It was Number Thirteen who introduced Zhang Zhenxing to Gao Yang, so the first person Gao Yang thought of to deal with Zhang Zhenxing was definitely Number Thirteen.
Gao Yang called Number Thirteen, but he was quite worried about whether he could get through, because Number Thirteen had said himself that his phone was not often reachable, especially when he was planning to complete a very complicated task, just as Gao Yang would only turn on his phone when necessary during a mission, Number Thirteen also had to avoid being disturbed while undertaking an important task.
Fortunately, the first time Gao Yang called, Number Thirteen answered.
Gao Yang was also very concerned about the whereabouts of Karima, so after Number Thirteen picked up, he immediately said, "Leonard?"
"It's me."
"How is the investigation going? Any progress?"