This paper argues that 'that-trace' effects, along with Aux-inversions, can be dealt with in the same as Subject Islands in English. In order to do this, it is proposed that (ⅰ) all the goals relevant to a C are simultaneously activated at a point of derivation where the C merges, (ⅱ) Merge of 'that' to a C forces the probe u[T] on the C to enter first into AGREE with the [T]-feature on a finite T, and (ⅲ) only activated features raise Intervention effects on AGREE. It is further claimed that each feature(i.e..probe) on a C has an EPP property only if the pied-piping of an element satisfying AGREE with the probe meets the Extension Condition.