In ATLAS, the very first component that is reached by colliding particles is the inner detector. As particles collide, their tracks, momentum and charge must be measured with the highest degree of precision. In this interview by ATLAS physicist Steven Goldfarb of colleague Pippa Wells, ATLAS Inner Detector System Project Leader, viewers learn how this measurement is done in the heart of ATLAS. Topics covered include a basic description of the structure of the inner detector, what the detector is trying to do, what types of particles will be able to be seen, how the inner detector records what it sees, what happens to the data collected, the construction and assembly process of the detector, the importance of system testing during assembly, and what would happen if the Higgs particle passed through the detector. Produced by: ATLAS OUTREACH Director: Yves-Rene Kayonga 4:30 min