In 2013, Jim and Sherrin began collecting the bodies of birds that had fallen victim to the silicon quartz that was growing in Ambermouth harbour — a by-product of Eldrad's presence. A beluga whale, infected by the crystal, was taken in by Sherrin and Jim, despite not having the appropriate facilities to house it. They named it Skipper and kept it in the centre where it was dosed with morphine. He grew temperamental at the Fifth Doctor and Nyssa being in the facility and was furious when Tegan stole his car.
Bob Gell, who had also been infected by the silicon quartz, transmitted this mutation to Jim, who crystal then began to grow on too. As with the other Ambermouth residents, Jim was cured when Eldrad's ring was destroyed alongside two of his incarnations. (AUDIO: Eldrad Must Die!)