"Fire in the woods!" The words are a real heart stopper. Yet in spite of its capacity to destroy, fire plays an essential role in shaping plant communities. Knowledge of the patterns of fire over long time periods is critical for understanding this role. Trees often retain evidence of nonlethal fires in the form of injuries or scars in the annual growth rings of their trunks. Careful analysis of these injuries and of tree recruitment and death dates (also determined from tree rings) can reveal a lot about the size, frequency, season, and severity of fire events over several centuries.