Bob and the gang are building the road connecting Bob's mobile home site with the location of the new yard. It's a big job for Roley, but just as Bob's explaining the job, a pretty little bird flies overhead clutching some twigs in her beak. The bird reminds Roley of his friend Bird back in Bobsville and he realises she's off to make a nest. Without listening to Bob, distracted Roley decides to follow the bird. As the rest of the team get to work, Roley realises that the bird is about to build her nest right in the path of the new road and He persuades the bird to find a new place for her nest. The bird moves on, but to an even worse place! At the road build, Bob starts to worry about Roley's whereabouts, he'll be needed soon. Roley, however, is still trying to move the bird to a safe nesting spot. Without realising, he rolls into a patch of mud and becomes stuck. Meanwhile the gravel layer of the road has been laid and need flattening. In Roley's absence, the other machines combine there efforts, and do a pretty good job. In the meantime Bob and Lofty set off to find the missing Roley. They call for Roley and eventually find him stuck in the mud. Lofty helps free Roley, as he explains what happened. Roley tries to show Bob the bird, although it becomes clear that the bird has flown away - probably frightened by Bob's calls. Bob, Lofty and Roley get back to the road, where the hot bitumen is just about ready to go. Roley, sad to have lost his new friend, suddenly hears a whistling sound! It's the bird! She's built her nest --and in the perfect, quiet spot. Roley is careful to make sure that the whole team give the nest plenty of space, and he declares himself the happiest steamroller in the whole world!