The corpus of carved ivories from the sanctuary of Orthia at Sparta forms one of the most cosmopolitan assemblages from Archaic Laconia. One image within this corpus, however, has remained an anomaly: a mirror-image scene on two plaques showing three figures mourning a deceased male in the prothesis ritual. The puzzling nature of these plaques rests on the dearth of imagery elsewhere in Laconia from this period displaying the prothesis, unlike Attica. These images have been viewed as representing a mythical death or a commemoration of an actual death, tied to a period in Sparta's history when elite groups claimed power through ostentatious ritual, but their overall meaning within Orthia's sanctuary remains obscure. I argue, however, that these plaques are not anomalies within the ivory corpus, nor are they divorced from the broader ritual programme in Orthia's sanctuary – rather, the ivory corpus itself represents a unified composition that merged scenes showing ideal activities for Spartan citizens with heroic episodes from myth, geared towards the achievement of everlasting kléos. The semantics of these combined iconographies are clarified via comparison with cultic implements described in ancient literature alongside extant examples of multi-scene figural pottery from the seventh and sixth centuries. This paper thus highlights the mythological and ideological meanings of the prothesis plaques within the broader ivory corpus, and elucidates the role of complex figural iconographies in the elaboration of heroic ideals centred on Spartan citizens in this period.