Extensive work has been done looking at how people reason causally and respond to information anomalous to their beliefs. However, little work has looked at how supportive and anomalous information interact when people evaluate the plausibility of a possible explanation. In this study, participants were given an event and either one or two possible explanations. Participants evaluated the plausibility of the explanation(s) repeatedly after exposure to combinations of supportive/non-supportive information and a strong/weak anomaly, producing a 2 (number of explanations) x 2 (presence of support) x 2 (strength of anomaly) design. The results showed that support initially increased plausibility and generally decreased the effect of anomalies. This was qualified by a 3-way interaction, which may be driven by how alternative explanations are evaluated relative to each other. The implications for future work, to understand how available information affects causal reasoning in everyday and professional contexts, are discussed.