Thetis not only mourns her son Achilles as if he were already dead: she formally laments him in song. The wording of the verses spoken by Thetis here at I.18.051–060 corresponds morphologically to the wording of a song that could actually be sung as a lament. Leading her Nereid sisters, Thetis begins the singing at I.18.051, as signaled by the verb ex-arkhein ‘lead off [in performing]’, which indicates a performance by a lead performer in a song of lament performed by a group (see also PH 362). In this case, that group is represented by the Nereid sisters of Thetis. Such a performance involves not only singing but also a kinetic system of stylized movements—which is a kind of dancing that is integrated with the singing. On this point, see already the anchor comment on I.08.407–439. The movements of this kind of a kinetic system can be formalized by way of gestures such as swaying, tearing the cheeks, beating the chest, and so on, and it must be kept in mind that the singing of lament could regularly include the kind of stylized dancing that I describe here. As for the overall practice of singing this kind of lament, it is indicated here by a special word, góos, I.18.051. As we will see when we encounter further occurrences of this word, the góos is ordinarily sung only by relatives or close friends of the person who died. A typical theme in such a lament is what we see being sung by Thetis here at I.18.056–057, evoking the image of a tender young seedling that has tragically been cut down before its time.