Abstract: In this last seminar, we shift our focus to the double-dimer model with the aim of building a space of local fields in the same fashion as we did for the DGFF in the previous talk. In this context, we introduce discrete-holomorphic observables that serve as building blocks for local fields. We interpret these observables as a discretization of symplectic fermions, and we prove their space of local fields to carry a representation of the Virasoro algebra with the central charge of the symplectic fermions CFT: -2. In the continuum, symplectic fermions are described by a CFT of logarithmic type (logCFT), whose name stems from the logarithmic dependencies that logCFTs feature in correlation functions. Alongside a more intricate analytic structure, logCFTs also possess a rather exotic algebraic content in the form of a reducible yet indecomposable representation of the Virasoro algebra.