Given an N = 2 superconformal field theory, we reconsider the Schur index I L (q) in the presence of a half line defect L. Recently Cordova-Gaiotto-Shao found that I L (q) admits an expansion in terms of characters of the chiral algebra A introduced by Beem et al., with simple coefficients v L,β (q). We report a puzzling new feature of this expansion: the q → 1 limit of the coefficients v L,β (q) is linearly related to the vacuum expectation values L in U(1) r -invariant vacua of the theory compactified on S 1 . This relation can be expressed algebraically as a commutative diagram involving three algebras: the algebra generated by line defects, the algebra of functions on U(1) r -invariant vacua, and a Verlindelike algebra associated to A. Our evidence is experimental, by direct computation in the Argyres-Douglas theories of type (A 1 , A 2 ), (A 1 , A 4 ), (A 1 , A 6 ), (A 1 , D 3 ) and (A 1 , D 5 ). In the latter two theories, which have flavor symmetries, the Verlinde-like algebra which appears is a new deformation of algebras previously considered.