# How do ADC/DACs deal with out of sync signals near Nyquist frequency?

Let's say a converter is sampling continuously at 48 kHz and the incoming waveform is a sine wave at 24 kHz... How does it faithfully recreate the waveform if the samples are taken at points that are 0?

Not at all. Things at $\frac{f_\text{sample}}2$ might just as well be constants. You can't tell [0 0 0 0] (sampled 24 kHz signal at zero-crossings) from [0 0 0 0] (sampled zero constant signal).