FeSe (Tc = 9 K) being structurally the simplest iron based superconductor shows some exotic properties. For instance, it only undergoes a tetragonal-to-orthorhombic structural transition at Ts = 90 K while no long range magnetic order develops down to the lowest measured temperature leaving the spin fluctuations mediated paring mechanism in doubt. Our recent inelastic neutron scattering experiment have revealed the presence of strong magnetic fluctuations in this system as well. Moreover, we have observed a strong coupling between spin fluctuations and nematicity. Here we propose to use MERLIN to map out the high energy spin excitations to determine the exchange couplings across Ts and we expect a modification of the magnetic exchange couplings below Ts, as suggested theoretically.