PCA lightcurves of long burst from 2S 0918-549 in two bandpasses and over the two active PCUs (top two panels) and the hardness ratio between both (third panel). The time resolution is 0.1 s for times earlier than 1 s, and 1.0 s for later times. The inset in the first panel shows the full-bandpass lightcurve for the first 60 ms at a time resolution of 1 ms with a rate in units of 10⁴ c s^-1.