Rebecca's Treasure is the eighth episode of the fourth season.
Theodore is sure that his assignment to work with Rebecca, The Research Vessel will be boring. He isn't sure exactly what Rebecca does, but he does know that he'd rather be with the other tugs bringing in a big ship. But when Rebecca locates something at the bottom of the Harbour, Theodore begins to get excited. When it turns out to be an old pirate ship anchor, Theodore realizes that Rebecca was right when she said that sometimes 'you just have to look a little deeper.' And he knows she means more than just looking underwater.
- This is the first time Theodore goes exploring with Rebecca.
- From this episode onward, Rebecca has a white face, moving eyes and a sonar dish.
- When the crew find the anchor, Rebecca's eye mechanism can be seen working in her windows.
- When Rebecca says "I don't always feel cheerful", a studio light can be seen in the upper left hand corner.