Adam and Dash find Tony Timms, intrepid reporter for the Mt. Thomas Gazette, dazed and injured on the riverbank while they are investigating a reported explosion. Tony's camera has gone but he won't say who attacked him or why he was there. But the Heelers get a clue after they attend a charity fish dinner at the Imperial, all of those who eat the fish come down with food poisoning. Could it be that the Mt. Thomas River is polluted? Sure enough, the Heelers discover some suspicious looking barrels in the river. But Doctor Zoe's tests show that the drum contents had nothing to do with the fish poisoning. Meanwhile, Chris reports that the Akubra hat containing the money collected at the charity dinner has gone missing. The suspects include Keith Purvis and his new lady love, a local pig farmer. Or was it Jeanie, the cook, resentful of the implication that she poisoned the fish? And how was Tony Timms and his keen youth trainee involved? Maggie and PJ realise they won't find the answers u