In sluicing, an interrogative clause is phonologically reduced to a wh-phrase, as in Sam is drinking something, but I don't know what. As much research has shown, sluicing has properties in common with, as well as properties not shared by, non-elliptical questions, leading to an ongoing debate about the nature of the ellipsis involved in sluicing. In this paper, I seek to contribute to this debate, offering a novel argument, based on Subjacency, against one main approach—PF Deletion (e.g., Ross 1969, Merchant 2001)—and arguing for a novel, Minimalist version of the second main approach, LF Copying. The Minimalist LF Copying proposal motivated here relies exclusively on externally-motivated operations of the grammar, including Agree (Chomsky 1995) and Sideward Movement (Nunes 1995), and addresses some of the criticisms that have been put forth in the literature against Chung, Ladusaw, and McCloskey's (1995) original LF Copying proposal. I also show that the novel LF Copying proposal realizes a significant empirical gain over PF Deletion where languages that violate the Preposition Stranding Generalization (Merchant 2001), such as Indonesian, are concerned.