Recently it has been reported that YbAl3C3 undergoes an antiferromagnetic quadrupolar ordering transition at 80 K, Further study by Ochiai et al. revealed that the transition at 80 K is related to a small structural change. They explained the non-magnetic ground state as due to a spin-gap formation in YbAl3C3 on the basis of an isolated dimer model. Very recent NQR/NMR studies by Mito et al. on YbAl3C3 reveal that its unique magnetic properties are consistent with the hypothesis that the microscopic mechanism underlying the phase transition involves Yb-4f electrons rather than the scheme of a simple structural. This then implies strong changes in the hybridization across the transition. We therefore propose to carry out inelastic neutron scattering investigations on YbAl3C3 using MERLIN to investigate the nature of 4f-electrons above and below the phase transition.