Chief Fire Officer Boyce announces that the old Pontypandy fire station will be closed down to make way for a new, more modern fire station and two new members of the firefighting crew. In the meantime, the team will have to co-ordinate rescues from a Mobile Command Unit whilst the new fire station is being built. Up at the mountains, Penny is taking Norman, Mandy, Sarah and James on a pot-holing trip in the old mines. And at the Mountain Activity Centre, Moose and Tom are using Mooses new amphibious vehicle to take wildlife photographs, but they havent quite mastered the controls and its not long before theyre swept out to sea and Sam has to come to their aid. Elsewhere at sea, Charlie and coastguard Ben see a hurricane has rapidly developed and is heading straight for Pontypandy; they immediately warn Sam. So its action stations as Sam has to rescue Penny and the kids from the old mines, Elvis helps prepare Pontypandy for the storm and Station Officer Steele gathers everyone at the new fire station. But when a fire breaks out at the new fire station, its a race against time as Sam has to hurry back to Pontypandy to help the rest of the team and save the day. The hurricane passes, Pontypandy made it through. As life goes back to normal in Pontypandy, Moose donates the amphibious vehicle to Sam and the team newly painted in fire station colours and re-named Hydrus.