There is a peculiar syntactic difference between focus phrases and relative words with respect to extractability from the TP-ellipsis site. In order to account for it, this paper suggests a novel analysis of TP-ellipsis which is based on three basic assumptions; First, the split CP periphery in the sense of Rizzi (1997, 2001, 2004) is derivationally constructed by means of Merge in a bottom-up fashion. Second, the TP-ellipsis site must undergo topicalization before ellipsis. Third, in the extended spirit of Johnson (2001), the topicalized phrase is adjoined to TopP, and so it becomes an adjunct island in the sense of Ross (1967). Under this theoretical framework, this paper argues that the extractability from the TP-ellipsis site depends on the landing site for the extracted element. The lower head projects before the higher head does in a derivational left periphery, and so extraction of a focus phrase from the TP-ellipsis site may occur before the TP in question moves to TopP. In contrast, extraction from the TP-ellipsis site to the edge of ForceP is impossible since it is done after the TP in question becomes an adjunct island. This paper also shows that its analysis can be extended to explaining embedded sluicing, split questions, left-dislocation, and the survival of topic phrase in sluicing.