It has been standardly claimed since Merchant (2001) that island violations can be repaired by simply deleting the categories that induce such violations, as witnessed by sluicing, an ellipsis construction that deletes TP with a remnant wh-phrase. This book aims to argue that such “repair by ellipsis” is simply a myth. Alternatively, the author argues for what is called the in-situ approach to sluicing, originally proposed by Kimura (2007, 2010), according to which the remnant wh-phrase in sluicing stays in situ. This approach immediately explains the island-insensitivity of sluicing, since no overt wh-movement is involved in the derivation of this construction. Hence, it challenges the approach in terms of island repair by ellipsis in that it nullifies the necessity of a repair mechanism. This book makes an important contribution to the field in providing an alternative way of approaching ellipsis phenomena that are claimed to induce “island repair.”