An in-pile power-cooling-mismatch (PCM) test designed to investigate the behavior of a nine-rod PWR-type fuel bundle under intermittent and sustained periods of high temperature film boiling operation was recently conducted. Emphasis was placed on departure from nucleate boiling (DNB) and return to nucleate boiling (RNB), rod-to-rod interactions, and fuel rod failure. Results indicate that power-coolant variations induced DNB and RNB within the nine-rod test bundle in an irregular, nonsymmetric fashion. Direct rod-to-rod DNB, RNB, and fuel rod failure propagation were not observed. However, a single rod-to-rod interaction was suspected, that being RNB of one rod abetting the onset of DNB on an adjacent rod. This interaction was possibly due to hydraulic coupling. The power and inlet coolant conditions at the onset of DNB on the center fuel rod were indistinguishable from previously obtained PCM data for separately shrouded test rods; thus, the single-rod data base may be applicable for assessing the onset of DNB conditions of an interior fuel rod within a small cluster.