The frustrated pyrochlore Er2Ti2O7 is a rare example of a magnetic system in which quantum fluctuations are capable of selecting a unique ground state out of the macroscopically degenerate manifold imposed by frustration. Thus, below 1.2 K the system sets into an ordered AFM ground state, which, on the hand, is highly unconventional for it is one in which short- and long-range ordering coexist and remains dynamic as T --> 0. Sn doping the non-magnetic Ti sublattice monotonically reduces the ordering temperature and seems to drive the system into a quantum critical point at x \simeq 1.8, as seen by ac-susceptibility measurements. As part of a wider study involving specific heat and susceptibility measurements, the aim of the proposed experiments is to confirm the existence of this QCP and check for some unusual changes in spin dynamics that seem to take place with Sn doping.