It is nearly Christmas on the Island of Sodor and it is a very busy day at Brendam Docks. Cranky is busy unloading cargo when he comes across a very heavy load which turns out to be Gator, Percy's friend. Salty is pleased to see Gator, but he knows that Percy will be even more excited to see his old friend. A load of rock salt has also been sent over on Gator's ship, but the delivery note has got wet and become unreadable during the transit. The dock manager thinks the salt is destined for the Blue Mountain Quarry and asks Gator to take it. Before he leaves, Gator asks Salty to let Percy know he is back if he sees him.
Gator meets Thomas at a junction. Thomas can't believe his eyes; he did not expect to see Gator again. Gator asks Thomas to tell Percy that he is back when he sees him. Thomas promises to do so. He knows that Percy will be very excited to see Gator again.
Thomas rushes into the shunting yard where Percy is busy shunting trucks. Thomas tells Percy that Gator is back. Percy is delighted and thinks it is sure to be the best Christmas ever. Percy asks where Gator is and Thomas says that he is currently making a delivery to the quarry. Percy decides that he will deliver himself the quarry in order to see Gator.
Up at the Blue Mountain Quarry, Gator has made his delivery. Owen is very pleased to see Gator again. Gator asks Owen to let Percy know that he is back on Sodor. Owen promises to do so. Then, Gator's driver explains that there has been a mistake; the rock salt isn't meant for the quarry. The driver assumes that the salt must be for the Sodor Steamworks. Gator heads off towards the steamworks, just as Percy pulls in at the quarry. Owen tells Percy that Gator has been there and he is heading for the steamworks so Percy sets off after his old friend.
At the steamworks, Gator's driver is told that the salt is not for them. A workman thinks the salt must be for the platforms at Knapford Station as they have a tendency to get very slippery in the winter. Gator heads off as Percy makes his way to the steamworks. The two friends even pass by one another and do not even notice. Gator is beginning to think that Percy doesn't want to see him after all. At the steamworks, Percy is told by Victor that Gator has been and gone again. Percy starts to wonder why Gator has been to see everyone else apart from him. Maybe Gator has forgotten all about him.
At Knapford, Gator meets Thomas who tells him that Percy is looking for him. Gator finds this hard to believe; if Percy really wanted to see him, he would've found him by now. Just then, the Fat Controller walks up and demands to know why Gator has brought the rock salt to Knapford. Gator's driver shows him the unreadable delivery note. The Fat Controller checks this with his notes and tells Gator that the rock salt was meant for Brendam Docks all along, to stop the docks being slippery in the winter. He tells Gator to take it back there as quickly as he can. Gator sets off. As Thomas pulls out of the station, he meets Percy who is very upset at the thought of being snubbed by his old friend. Thomas explains that Gator wants to see Percy as much as Percy wants to see him and tells Percy that Gator is heading back to the docks. Percy thinks Gator is leaving again and races off as fast as he can for the docks.
Percy speeds into the docks just in time to see the ship depart. He has missed Gator once again. Percy puffs forwards, shouting at the ship. Due to the fog, Percy cannot see the train of rock salt until it is too late. Percy collides with the train, sending bags of salt flying all over the docks. Then, Percy discovers Gator, covered in bags of rock salt, at the other end of the train. Percy is thrilled. Gator says that this time, he plans to stay on Sodor at least long enough to have the salt cleaned off of him. Salty rolls up and jokes that they can't have two Salties on Sodor causing all 3 engines to laugh. Percy will have a very happy Christmas now that he has been reunited with his old friend.