  Electronic tunability in crystals with weakly-bound layers can be achieved
through layer stacking order. One such example is MoTe$_2$, where the
low-temperature orthorhombic T$_d$ phase is topological and host to Weyl
quasiparticles. The transition mechanism to the non-trivial topology is
elucidated by single crystal neutron diffraction. Upon cooling from the
monoclinic 1T$\prime$ to the T$_d$ phase, diffuse scattering accompanies the
transition, arising from random, in-plane layer displacements, and dissipates
upon entering the T$_d$ phase. Diffuse scattering is observed only in the H0L
plane due to irreversible layer shifts along the c-axis that break the
centrosymmetry of the monoclinic lattice.
