The particular bacterium if infecting the skin is fairly treatable and mild with modern medicine, pneumonic plague is 100% lethal if not treated within 24h and utterly asymptomatic during the first 24h, it’s also airborne. Same bacterium but very different diseases..

> pneumonic plague is 100% lethal if not treated within 24h and utterly asymptomatic during the first 24h

But isn't the 24 hour critical window of treatment measured from the onset of symptoms?