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ASASSN-14ko is a recently discovered comma periodically flaring comma nuclear transient within known AGN ESO 253-G003. The flares have a mean period of virgul114 days and a nonzero comma negative period derivative. The exact origin of these UV-optical flares is currently V1.0. Here we propose a four epoch STIS UV set of observations of the next predicted flare in December 2020. The prior 6+ years of seventeen observed flares seen in ASAS-SN tightly constrains the predicted times of pre-flare quiescence comma rise comma peak comma and decline. These observations will be part of a much larger followup effort but the UV spectroscopy is pivotal. We will measure the evolution of UV absorption and emission lines from elements (e.g. comma C comma N comma Si) and ionization states-potentials not seen in optical spectra comma which will directly help distinguish whether or not these flares are caused by a partial TDE comma AGN disk accretion comma or another high energy phenomenon.