In truth, Su Bai had never suspected from the beginning that it was a probe. He never thought they would purposely stage a drama for himself.
From the moment Sofia called him to the moment she was already in the elevator when he opened the door. As well as the moment she invited Su Bai to join her to the vampire club after receiving a call.
Su Bai had thought that he was lucky. He wasn't Sherlock Holmes[1] and he couldn't discover the minutest detail in everything. The other party had been too prudent, so prudent that it was borderline excessive. Perhaps they were panicky, over-panicky when they discovered himself, on no, Lucky and himself getting off the plane in London. They couldn't sit still; they had no time to brush up their acting skills and had many loopholes in their acting.
A series of coincidences could no longer be innocently treated as a coincidence any longer.
The most obvious was Sophia's IQ...
[1] Sherlock Holmes is a fictional private detective created by British author Sir Arthur Conan Doyle. Referring to himself as a "consulting detective" in the stories, Holmes is known for his proficiency with observation, forensic science, and logical reasoning that borders on the fantastic, which he employs when investigating cases for a wide variety of clients, including Scotland Yard.
[2] English Premier League is the top level of the English football league system. Contested by 20 clubs, it operates on a system of promotion and relegation with the English Football League (EFL). The Premier League is a corporation in which the member clubs act as shareholders. Seasons run from August to May with each team playing 38 matches (playing each other home and away). Most games are played on Saturday and Sunday afternoons.
[3] Execution by firing squad.