of top panel). Simultaneously, the hardness ratio (the $3-10$[[keV]{}]{}rate over the $0.3-1$[[keV]{}]{}rate) evolves dramatically. As the count-rate begins to rise, the hardness ratio spikes. Subsequently, the hardness briefly dips, and then stabilizes. It is during the dip that the pause in count-rate is observed. Additionally, the previously mentioned dip in count-rate (at $t\simeq13{{\rm\,s}\xspace}$), coincides with a similar dip in the hardness ratio, suggesting these two features are related.

![ Top: light curve of the X-ray burst from [SAX J1808]{} at $0.1{{\rm\,s}\xspace}$ time-resolution in the $0.3-10$ keV energy band. Bottom: hardness ratio, defined as the $3-10$ keV rate divided by the $0.3-1$ keV rate. Inset: first four seconds of the same data, with the light curve in black (connected line, units of $\times10^{4}$[ct[s$^{-1}$]{}]{}) and the hardness ratio in red (vertical dashes). All panels are relative to $t_0=58716.089362$TDB. Vertical gray lines were added to guide the eye. []{data-label="fig:lc"}](burst-light-curve.pdf){width="\linewidth"}

Pre-burst emission {#sec:preburst}
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We extracted a spectrum from $400{{\rm\,s}\xspace}$ prior to the burst and modelled it in <span style="font-variant:small-caps;">xspec</span> v12.10 [@Arnaud1996]. Following @DiSalvo2019, we find that the spectrum could be well described with the model

> `tbabs( diskbb + nthcomp )`,

where the `tbabs` interstellar absorption model [@Wilms2000] was used with the photoelectric 