We first review the interpretation of world sheet defects as D branes described by a critical theory in 11 dimensions, that we interpret as M theory. We then show that D-brane recoil induces dynamically an anti-de Sitter (AdS) space–time background, with criticality restored by a twelfth timelike dimension described by a Liouville field. Local physics in the bulk of this AdS11 may be described by an Osp (1|32, R) ⊗ Osp (1|32, R) topological gauge theory (TGT), with nonlocal boundary states in doubleton representations. We draw analogies with structures previously exhibited in two-dimensional black hole models. Wilson loops of "matter" in the TGT may be described by an effective string action, and defect condensation may yield string tension and cause a space–time metric to appear.