It was spring in the Big Harbour. The tugs just woke up a good mood. The Dispatcher told them there are no jobs today but there's a new girl coming to the Harbour. The tugboats are puzzle and excited. Hank ask who's a new girl in the Harbour. The Dispatcher told him the new tugboat girl name is Lucy. Theodore was excited and know her, he explained to his friends he had been her brother for a long time since he lives at his old home. He told them she's kind, she likes to go on adventures and like to solve mysteries and tried to solve who is the mystery guest. Foduck ask is Lucy a big or small tug, Theodore said she's a small tugboat like him and Hank. Hank is too excited and wants to meet her. The Dispatcher told them she'll be coming soon a minute. So Foduck decided to use his firehose to make himself and his friends look nice so they can meet her. By 20 minutes the tugboats are still waiting for the new tugboat arrived, so they decide to play freeze tag while they wait. Hank goes first to be it to catch the tugs, all the tugs float away fast they can. When Theodore got away from Hank and went too far he didn't pay attention where he was going, he bump into Blandford the bell buoy. Theodore apologize and didn't watch he was going but Blandford except his apologize. Than Theodore begin to turn home and gasps; it was Lucy, Theodore's old sister of his. Lucy and Theodore are been reunited and glad to see each other. Theodore ask her what she is doing here. Lucy explain she been lonely since Theodore left at his old place in the Harbour and not at same without him, so she decided to go live with him and work very hard. Theodore is glad to hear this and happy to see his friend coming to stay with him. So Theodore and Lucy to the Harbour together so Lucy can meet Theodore's friends. At the Big Harbour tugs are searching for their missing friend they were worried, than Hank spotted Theodore is back and brought a new tugboat. So everyone glad Theodore is all right, Theodore introduce his old friend Lucy. Theodore let Lucy introduce his friends, Lucy couldn't understand about v-tugs. So George explain is any tugs works so hard and get it right they will be bigger and get they're v-words and go out to the open ocean to sea the world. Lucy was amazed and delighted if she works very hard, she'll get a v-word until she's a bigger tug to go out the open ocean. So tugs show Lucy around the Harbour introduce their friends, Theodore is happy to see his friends again. After the end of the day they got very tired and went back the docks, Lucy felt she'll would never belong to the dock. So the tugs tell Lucy to stay with them Lucy is very happy, Theodore and Hank let Lucy sleep with them in the dock. So Lucy snuggle close to Theodore and smiled and went to sleep. Emily smiled at Lucy but she is worry that Theodore doesn't cared about her no more so she went to sleep. The next day Emily woke up a good morning but than she shock, Theodore and Lucy are going exploring together around the Harbour. Emily felt disapointed and she stays at the dock doing nothing. Early Emily wants Theodore to go race around Willy's Island but Theodore said yes so they racing around Willy's Island. Than Lucy came up to them and ask she wants to race too, they say yes join racing around Willy's Island. Emily ask Theodore if she can go see some fish at Shipwreck Rock with him but Theodore told her maybe later he had to take Lucy meet Rebecca go treasure hunt. This time Emily became a little upset. Another day, Emily went around the Harbour floating around doing nothing just stare at the clouds in the sky. Theodore float up to Emily asking her what's matter, but she said nothing just looking at the clouds. Theodore ask Emily if she can go exploring after the morning work meeting, so Emily says yes delighted go exploring. After exploring they arrived they morning work meeting just in time, Emily hope that Theodore is not going to hang around with Lucy again. Emily ask the Dispatcher if she can help Theodore to Lucy show her everthing, but the Dispatcher said Theodore is going to the show her around the Harbour and told her take over Theodore's job to move Barrington Barge. But Emily is very unhappy she didn't want to do a small job and now she is jealous of Lucy for hang around with him. By afternoon Emily is floating very quiet and still upset that Theodore is hanging around with Lucy. Theodore and Lucy came up to Emily to ask she join go visits Celiodh's Cove but Emily shout at them and says no. Theodore ask her what's wrong but Emily is still mad and won't talk to him. Theodore thought Emily is mad at him so he's going to find out tomorrow. The other day Emily is towing Bedford Buoy with a new bell and than she saw Theodore and Lucy hang around and laughing, but Emily just ignored them when Carla and Sigrid arrived they saw Emily very upset. Emily explain to them what had happened when Theodore is hanging with Lucy the new tugboat. Sigrid felt sorry for her and Carla told her that she is jealous of Lucy and Emily had to agree she is jealous, but Emily is glad her friends cared about her went racing at Shipwreck Rock together. When its getting late Emily went to go home than Theodore came up to her, but Emily still upset with him but Theodore made a stern voice and ask her what's wrong. Emily didn't answer but Theodore ask her again one last time. But Emily snap at him and told him she is jealous of Lucy for hanging around with her instead spend with her. Theodore heard this he's begin to get upset he was trying to let Lucy like her new home. Emily shouted angry he suppose to hang around with her not spending time with Lucy. Theodore told her she's just jealous; Emily said she is if he likes Lucy more than her than she stop talking to him and be friends with him. Theodore said the same went back home very upset, Emily turn away with tears in her eyes. At night Emily couldn't sleep still upset that Theodore didn't care about her no more, so she decide to run away from home and never return. Emily look Theodore sleeping she still mad and look at Lucy she's felt sad but she gave Lucy one of her pink seashells to put up on her dock. Emily softly goodbye and left when the tugs woke up in the morning work evening, George cried out that Emily is disappeared. Out of the ocean Emily had to find a hiding place so no can find her so she find spot that never use before she begin to go in. At the big harbour, everyone is looking for Emily they were all very worried. Theodore felt gulity for being hard on her, Carla told him its his fault not spend time with her and loving her instead of hang around with Lucy. Lucy felt guilty what she had done, Theodore no longer can't take it anymore he had to find Emily because he loves her and he needs her. So they decide to split up but Lucy wants to look for Emily herself, Theodore tells her to be careful and watch out for danger. Out of the ocen, Emily resting at old cove with giant tree logs cause she didn't get much sleep last night. At the other side in the Harbour, Lucy is looking for Emily and couldn't find her anywhere. She look worried and felt it was her fault that she took Theodore away from her. Than she notice that she had a pink seashell on her deck, Lucy thought Emily give this to her because she thought Theodore like her than Emily. She called out to Emily but nothing no sign of her. At the old cave with giant tree logs Emily still resting than a bang noise, when Emily heard this she felt scared that this old cave is about to fall apart so Emily race out of the cave. When Emily is out to reach out one of big tree logs fall on top of her, Emily tried to move but she is stuck her had broken. Poor Emily felt terrible she shouldn't ran away from home now she miss her friends at the Harbour. Lucy couldn't find Emily anywhere she look worried. So she use her whistle to toot louder than Emily heard Lucy's whistle she is proud than she toot her whistle so loud, when Lucy heard Emily's whistle she jump for joy and follow the whistle. Emily toot her whistle again and again and again but she had stop and ran out of breath. When she saw Lucy she is happy and Lucy found Emily she is happy to see her. Emily apologize to Lucy for not being a good friend and jealous her and wants her to be her friend. Lucy smiled and told her she will her friend no matter what. Lucy told her everyone is worried and looking for her and Theodore is very worried. Emily is surprise, is Theodore miss her and worried about her? Well Emily didn't want Theodore and everyone to be worried than she decided to come home. Lucy smiled but Emily told her she can't move cause she stuck and her engine broke and couldn't move. So Lucy use towrope to get her out, she ask Emily give her another towrope to pull her out. At the Big Harbour, everyone felt tired and worried and couldn't find Emily anywhere Theodore felt ashamed what he had done and he really miss her a lot. Carla spotted Lucy found Emily and everyone is happy that Emily is safe. Emily went to sleep cause she didn't get much sleep last night, Foduck told Theodore Emily to Repair Dock and he'll take Lucy home. Theodore took Emily to Repair Dock, he told her he is sorry but she didn't hear she still a sleep. The next day when Emily slowly open her eyes and wake up she saw her friends Hank, George, Lucy, and Foduck they were happy. Emily wants to know why her friends are here, they said they worried and glad she safe and they miss her, Emily miss them too and glad to be home again. After Emily is fix she went exploring around the Harbour herself than Theodore came up to her. Emily is surprise, Theodore apologize for being hard on her and didn't do anything with her. Emily apologize too for being for hang around with Lucy. She told him she thought like Lucy more than her and didn't think he cares about her no more. Theodore told her that because Lucy is Theodore's old friend doesn't mean he won't stop being friends with her, he cared about her, love her, and always be friends. Emily's tears came out of her eyes and happy, she will always be his friend and love him cause she needs him. They share a love kiss and worshipped they're mouths when Lucy saw Theodore and Emily kissing, she's smiled and happily sigh. The next day, Theodore and Emily went exploring around the Harbour. Theodore ask Emily if they can go Shipwreck Rock, she says yes but one thing Emily ask Lucy is she can go Shipwreck Rock with her and Theodore. Lucy says yes glad and Emily told her she is her friend; but Lucy told her not just friends, best friends. Hank came up to them and told them the Harbour Master's youngest son has a new friend its a girl and have feelings for her. Everyone smiled and Hank told them he bought a special bracelet for her and welcome her to U.K Canada, everyone is excited and wants to meets a new friend Hank told wait til Saturday cause they're at school and went back home to tell George and Foduck. Foduck watch Lucy go with her new friends his cheeks are reddish pink. The three friends set off to explore around Shipwreck Rock, Emily is happy she's friends with Theodore again and most of all she is happy that she is Lucy's new best friend.