This paper attempts to explain why indirect objects and aspectual se in Spanish are ungrammatical in the periphrastic passive. The claim is that se is accusative and since accusative is not available in passive, these se are ungrammatical in passive. An appeal to parallel patterns by indirect object la of laísta dialects of Spain, which is overtly accusative, lends support to this approach. The technical account of accusative case on indirect object se relies on Multiple Agree with v. The Multiple Agree account generates concrete predictions regarding (non-)intervention effects with ethical, benefactive and alienable possessor datives. These predictions are tested and the results are positive, supplying support to the overall analysis.