We derive Einstein’s field equations as emergent from a timeless Euclidean model on four-dimensional Euclidean space E^4 with a single fundamental scalar field Phi satisfying the Laplace equation Delta_E4 Phi = 0. Building on an operational reconstruction of Lorentz transformations for observable transformations M on a fixed slice, we then allow slow variation of the foliation direction n_A(x) and introduce an effective Lorentzian metric g_AB defined in terms of the unit normal n_A and the induced Euclidean metric h_AB.A compensation principle, expressed as delta S_eff + delta S_g = 0 and imposed under the assumptions of locality, diffeomorphism invariance and at most second order in derivatives, together with preservation of the null cone under M on each slice, uniquely fixes the second-order local density. Using the Gauss—Codazzi identities, this density is equivalent to the Einstein—Hilbert action with the Gibbons—Hawking—York boundary term. Variation of the total action yields field equations of the form G_AB + Lambda g_AB = 8 pi G T_AB^eff with covariant conservation nabla^A T_AB^eff = 0; the Newtonian limit fixes the normalization of G.The requirement of causal reconstruction implies a hierarchy of length scales, L_field << L_fol, and the recovery of the Newtonian limit, as well as the universality of gravity: all effective fields couple minimally through the same metric g. This renders field-dependent light cones observationally inadmissible and ensures falsifiability. In addition, we obtain a local upper bound on the hierarchy parameter epsilon = L_field / L_fol <= epsilon_max << 1, which leads to testable bounds on deviations from the special- and general-relativistic regime.