sherlock holmes deduces you are trans before you’ve figured it out yourself and refers to you with those pronouns and then when you look confused is like “ah…had you not arrived at that conclusion yet?” and wafts away in his dressing gown to smoke seventeen pipes, leaving you in a gender crisis
Hercule Poirot deduces you are trans by accident because he suspected you of murder and broke into your house and searched your stuff then puts 2 and 2 together when Hastings makes an innocuous observation about your fashion sense or something and he jumps up and cries “mon dieu!!!” before striding over to you kissing you on both cheeks and saying “ah, cher ami, you must live as you choose!” and then running off to confront the real culprit while you stand there in befuddlement
Columbo deduces you’re trans from context clues while he’s talking to you about the area, immediately uses your preferred pronouns and starts telling you about his cousin, who’s also transgender, and how they got this job doing security, and how they told him that a security guard always locks up, and asks you if the guard locked up last night, and isn’t it weird the place was open? And you’re like, well, someone else must have opened it up. Maybe the guy in charge? He has a spare key. And then he nods and goes “the guy in charge has a spare key… well, how about that?” And then he offers you a cigar and wanders off, and a day later your boss gets arrested for murder.