Quantum phase transitions have recently received a lot of interest in various different fields of physics and the emergent universal properties have been studied in very different systems. Examples include 2D gases in semiconductor heterostructures, superfluid- or metal-insulator transitions, non-Fermi liquid behaviors or the condensation of quasi-particles in magnetic insulators. In our experiment we propose to study one particular field induced quantum critical point in a quasi-one-dimensional quantum magnet by means of inelastic neutron scattering. This will allow us to study in detail the dynamics in the quantum critical regime. (So far only static properties have been studied.) For the quantum critical point we will focus on, very strong theoretical predictions are available. Hence a quantitative comparison between experiment and theory will become possible.