 With no time to lose, Sarah Jane makes contact with Clyde, Rani and K9 and after explaining the Rakweed's weakness, they decide to use Mr Smith and K9 to activate all sound-producing devices in the area at the loudest possible frequency.K9 gives Mr Smith the frequency for the school bell and within seconds, all bells, alarms, radios and car alarms go off and the loudness ultimately destroys all the Rakweed.Luke is immediately cured and Sarah Jane is relieved to see him well again.